Geo chapter01power point

104
Patterns and Inductive Reasoning (For help, go the Skills Handbook, page 715.) GEOMETRY LESSON 1-1 Here is a list of the counting numbers: 1, 2, 3, 4, 5, . . . Some are even and some are odd. 1. Make a list of the positive even numbers. 2. Make a list of the positive odd numbers. 3. Copy and extend this list to show the first 10 perfect squares. 12 = 1, 22 = 4, 32 = 9, 42 = 16, . . . 4. Which do you think describes the square of any odd number? It is odd. It is even. 1-1

Transcript of Geo chapter01power point

Page 1: Geo chapter01power point

Patterns and Inductive ReasoningPatterns and Inductive Reasoning

(For help, go the Skills Handbook, page 715.)

GEOMETRY LESSON 1-1GEOMETRY LESSON 1-1

Here is a list of the counting numbers: 1, 2, 3, 4, 5, . . .Some are even and some are odd.

1. Make a list of the positive even numbers. 

2. Make a list of the positive odd numbers. 

3. Copy and extend this list to show the first 10 perfect squares. 12 = 1, 22 = 4, 32 = 9, 42 = 16, . . .

4. Which do you think describes the square of any odd number? It is odd. It is even.

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Page 2: Geo chapter01power point

Patterns and Inductive ReasoningPatterns and Inductive Reasoning

1. Even numbers end in 0, 2, 4, 6, or 8: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, . . .

2. Odd numbers end in 1, 3, 5, 7, or 9: 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, . . .

3. 12 = (1)(1) = 1; 22 = (2)(2) = 4; 32 = (3)(3) = 9; 42 = (4)(4) = 16; 52 = (5)(5) = 25; 62 = (6)(6) = 36; 72 = (7)(7) = 49; 82 = (8)(8) = 64; 92 = (9)(9) = 81; 102 = (10)(10) = 100

4. The odd squares in Exercise 3 are all odd, so the square of any odd number is odd.

GEOMETRY LESSON 1-1GEOMETRY LESSON 1-1

Solutions

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Page 3: Geo chapter01power point

Patterns and Inductive ReasoningPatterns and Inductive ReasoningGEOMETRY LESSON 1-1GEOMETRY LESSON 1-1

Each term is half the preceding term. So the next two terms are

48 ÷ 2 = 24 and 24 ÷ 2 = 12.

Find a pattern for the sequence. Use the pattern to

show the next two terms in the sequence.

384, 192, 96, 48, …

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Page 4: Geo chapter01power point

Patterns and Inductive ReasoningPatterns and Inductive Reasoning

Make a conjecture about the sum of the cubes of the first 25

counting numbers.

Find the first few sums. Notice that each sum is a perfect square and that the perfect squares form a pattern.

13 = 1 = 12 = 12

13 + 23 = 9 = 32 = (1 + 2)2

13 + 23 + 33 = 36 = 62 = (1 + 2 + 3)2

13 + 23 + 33 + 43 = 100 = 102 = (1 + 2 + 3 + 4)2

13 + 23 + 33 + 43 + 53 = 225 = 152 = (1 + 2 + 3 + 4 + 5)2

The sum of the first two cubes equals the square of the sum of the first two counting numbers.

GEOMETRY LESSON 1-1GEOMETRY LESSON 1-1

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Patterns and Inductive ReasoningPatterns and Inductive ReasoningGEOMETRY LESSON 1-1GEOMETRY LESSON 1-1

This pattern continues for the fourth and fifth rows of the table.13 + 23 + 33 + 43 = 100 = 102 = (1 + 2 + 3 + 4)2

13 + 23 + 33 + 43 + 53 = 225 = 152 = (1 + 2 + 3 + 4 + 5)2

So a conjecture might be that the sum of the cubes of the first 25 counting numbers equals the square of the sum of the first 25 counting numbers, or (1 + 2 + 3 + … + 25)2.

The sum of the first three cubes equals the square of the sum of the first three counting numbers.

(continued)

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Page 6: Geo chapter01power point

Patterns and Inductive ReasoningPatterns and Inductive Reasoning

The first three odd prime numbers are 3, 5, and 7. Make and

test a conjecture about the fourth odd prime number.

The fourth prime number is 11.

One pattern of the sequence is that each term equals the preceding term plus 2.

So a possible conjecture is that the fourth prime number is 7 + 2 = 9.

However, because 3 X 3 = 9 and 9 is not a prime number, this conjecture is false.

GEOMETRY LESSON 1-1GEOMETRY LESSON 1-1

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Patterns and Inductive ReasoningPatterns and Inductive Reasoning

The price of overnight shipping was $8.00 in 2000, $9.50 in

2001, and $11.00 in 2002. Make a conjecture about the price in 2003.

Write the data in a table. Find a pattern.

2000

$8.00

2001 2002

$9.50 $11.00

Each year the price increased by $1.50.

A possible conjecture is that the price in 2003 will increase by $1.50.

If so, the price in 2003 would be $11.00 + $1.50 = $12.50.

GEOMETRY LESSON 1-1GEOMETRY LESSON 1-1

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Patterns and Inductive ReasoningPatterns and Inductive ReasoningGEOMETRY LESSON 1–1GEOMETRY LESSON 1–1

pages 6–9  Practice and Problem Solving

1. 80, 160

2. 33,333; 333,333

3. –3, 4

4. ,

5. 3, 0

6. 1,

7. N, T

8. J, J

9. 720, 5040

10. 64, 128

11. ,

1 16

1 32

1 36

1 49

12. ,

13. James, John

14. Elizabeth, Louisa

15. Andrew, Ulysses

16. Gemini, Cancer

17.

18.

15

16

19. The sum of the first 6 pos.

even numbers is

6•7, or 42.

20. The sum of the first 30 pos.

even numbers is

30•31, or 930.

21. The sum of the first 100

pos. even numbers is

100•101, or 10,100.

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Patterns and Inductive ReasoningPatterns and Inductive ReasoningGEOMETRY LESSON 1–1GEOMETRY LESSON 1–1

22. The sum of the first

100 odd numbers is

1002, or 10,000.

23. 555,555,555

24. 123,454,321

25–28. Answers may vary.

Samples are given.

25. 8 + (–5 = 3) and 3 > 8

26. • > and • >

27. –6 – (–4) Ò –6 and

–6 – (–4) Ò –4

28. ÷ = and is

improper.

29. 758F

30. 40 push-ups;

answers may vary.

Sample: Not very

confident, Dino may

reach a limit to the

number of push-ups

he can do in his

allotted time for

exercises.

31. 31, 43

32. 10, 13

33. 0.0001, 0.00001

34. 201, 202

35. 63, 127

36. ,

37. J, S

38. CA, CO

39. B, C13

12

13

13

12

12/ /

/

12

13

32

32

3132

6364

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Patterns and Inductive ReasoningPatterns and Inductive ReasoningGEOMETRY LESSON 1–1GEOMETRY LESSON 1–1

40. Answers may vary.

Sample: In Exercise

31, each number

increases by increasing

multiples of 2. In Exercise

33, to get the next term,

divide by 10.

41.

You would get a third line

between and parallel to

the first two lines.

42.

43.

44.

45.

46. 102 cm

47. Answers may vary. Samples are given.a. Women may soon outrun

men in running competitions.b. The conclusion was based

on continuing the trend shown in past records.

c. The conclusions are based on fairly recent records for women, and those rates of improvement may not continue. The conclusion about the marathon is most suspect because records date only from 1955.

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Patterns and Inductive ReasoningPatterns and Inductive ReasoningGEOMETRY LESSON 1–1GEOMETRY LESSON 1–1

48. a.

b. about 12,000 radio stations in 2010

c. Answers may vary. Sample: Confident; the pattern has held for several decades.

49. Answers may vary. Sample: 1, 3, 9, 27, 81, . . .1, 3, 5, 7, 9, . . .

50. His conjecture is probably false because most people’s growth slows by 18 untilthey stop growing somewhere between 18 and 22 years.

51. a.

b. H and Ic. a circle

52. 21, 34, 5553. a. Leap years are years

that are divisible by 4.b. 2020, 2100, and 2400c. Leap years are years

divisible by 4, except the final year of a century which must be divisible by 400. So, 2100 will not be a leap year, but 2400 will be.

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Patterns and Inductive ReasoningPatterns and Inductive ReasoningGEOMETRY LESSON 1–1GEOMETRY LESSON 1–1

54. Answers may vary.Sample:

100 + 99 + 98 + … + 3 + 2 + 1 1 + 2 + 3 + … + 98 + 99 + 100 101 + 101 + 101 + … + 101 + 101 + 101

The sum of the first 100 numbers is

, or 5050.

The sum of the first n numbers is .

55. a. 1, 3, 6, 10, 15, 21b. They are the same.c. The diagram shows the product of n

and n + 1 divided by 2 when n = 3. The result is 6.

100 • 1012

n(n+1)2

d.

56. B

57. I

58. [2] a. 25, 36, 49b. n2

[1] one part correct

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Patterns and Inductive ReasoningPatterns and Inductive ReasoningGEOMETRY LESSON 1–1GEOMETRY LESSON 1–1

59. [4] a. The product of 11 and a three-digit number that

begins and ends in 1 is a four-digit number

that begins and ends in 1 and has middle digits that are each one

greater than the middle digit of the three-digit

number.(151)(11) = 1661(161)(11) = 1771

b. 1991

c. No; (191)(11) = 2101

[3] minor error in explanation

[2] incorrect description in part (a)

[1] correct products for (151)(11), (161)(11), and (181)(11)

60-67.

68. B

69. N

70. G

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Patterns and Inductive ReasoningPatterns and Inductive ReasoningGEOMETRY LESSON 1-1GEOMETRY LESSON 1-1

Find a pattern for each sequence.

Use the pattern to show the next

two terms or figures.

1. 3, –6, 18, –72, 360

2.

Use the table and inductive reasoning. Make a conjecture about each value.

3. the sum of the first 10 counting numbers

4. the sum of the first 1000 counting numbers

Show that the conjecture is false by finding one

counterexample.

5. The sum of two prime numbers is an even number.

–2160; 15,120

55

500,500

Sample: 2+3=5, and 5 is not even

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Page 15: Geo chapter01power point

Points, Lines, and PlanesPoints, Lines, and Planes

(For help, go to the Skills Handbook, page 722.)

Solve each system of equations.

1. y = x + 5 2. y = 2x – 4  3. y = 2x 

y = –x + 7 y = 4x – 10 y = –x + 15

4. Copy the diagram of the four points A, B, C,

and D. Draw as many different lines as you

can to connect pairs of points.

GEOMETRY LESSON 1-2GEOMETRY LESSON 1-2

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Points, Lines, and PlanesPoints, Lines, and Planes

1. By substitution, x + 5 = –x + 7; adding x – 5 to both sides results in 2x = 2; dividing both sides by 2 results in x = 1. Since x = 1, y = (1) + 5 = 6. (x, y) = (1, 6)

2. By substitution, 2x – 4 = 4x – 10; adding –4x + 4 to both sides results in –2x = –6; dividing both sides by –2 results in x = 3. Since x = 3, y = 2(3) – 4 = 6 – 4 = 2. (x, y) = (3, 2)

3. By substitution, 2x = –x + 15; adding x to both sides results in 3x = 15; dividing both sides by 3 results in x = 5. Since x = 5, y = 2(5) = 10. (x, y) = (5, 10)

4. The 6 different lines are AB, AC, AD, BC, BD, and CD.

Solutions

GEOMETRY LESSON 1-2GEOMETRY LESSON 1-2

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Page 17: Geo chapter01power point

Points, Lines, and PlanesPoints, Lines, and Planes

Any other set of three points do not lie on a line, so no other set of three points is collinear.

For example, X, Y, and Z and X, W, and Z form triangles and are not collinear.

In the figure below, name three points that are

collinear and three points that are not collinear.

GEOMETRY LESSON 1-2GEOMETRY LESSON 1-2

Points Y, Z, and W lie on a line, so they are collinear.

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Points, Lines, and PlanesPoints, Lines, and Planes

You can name a plane using any three or more points on that plane that are not collinear. Some possible names for the plane shown are the following:

plane RST

plane RSU

plane RTU

plane STU

plane RSTU

Name the plane shown in two different ways.

GEOMETRY LESSON 1-2GEOMETRY LESSON 1-2

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Page 19: Geo chapter01power point

Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1-2GEOMETRY LESSON 1-2

As you look at the cube, the front face is on plane AEFB, the back face is on plane HGC, and the left face is on plane AED.

The back and left faces of the cube intersect at HD.

Planes HGC and AED intersect vertically at HD.

Use the diagram below. What is the intersection of plane HGC

and plane AED?

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Page 20: Geo chapter01power point

Points, Lines, and PlanesPoints, Lines, and Planes

Points X, Y, and Z are the vertices of one of the four triangular faces of the pyramid. To shade the plane, shade the interior of the triangle formed by X, Y, and Z.

Shade the plane that

contains X, Y, and Z.

GEOMETRY LESSON 1-2GEOMETRY LESSON 1-2

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Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1–2GEOMETRY LESSON 1–2

1. no

2. yes; line n

3. yes; line n

4. yes; line m

5. yes; line n

6. no

7. no

8. yes; line m

pages 13–16 Practice and Problem Solving

9. Answers may vary. Sample: AE, EC, GA

10. Answers may vary. Sample: BF, CD, DF

11. ABCD

12. EFHG

13. ABHF

14. EDCG

15. EFAD

16. BCGH

17. RS

18. VW

19. UV

20. XT

21. planes QUX and QUV

22. planes XTS and QTS

23. planes UXT and WXT

24. UVW and RVW

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Page 22: Geo chapter01power point

Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1–2GEOMETRY LESSON 1–2

25.

26.

27.

28.

29.

30. S

31. X

32. R

33. Q

34. X

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46. Postulate 1-1: Through any two points there is exactly one line.

47. Answer may vary.Sample:

48.

49. not possible

Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1–2GEOMETRY LESSON 1–2

35. no

36. yes

37. no

38. coplanar

39. coplanar

40. noncoplanar

41. coplanar

42. noncoplanar

43. noncoplanar

44. Answers may vary. Sample: The plane of the ceiling and the plane of a wall intersect in a line.

45. Through any three noncollinear points there is exactly one plane. The ends of the legs of the tripod represent three noncollinear points, so they rest in one plane. Therefore, the tripod won’t wobble.

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50.

51. not possible

52.

yes53.

yes

Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1–2GEOMETRY LESSON 1–2

56.

no

57.

no

58.

yes

54.

no

55.

yes

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Page 25: Geo chapter01power point

Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1–2GEOMETRY LESSON 1–2

68. Answers may vary. Sample:

Post. 1-3: If two planes intersect, then they intersect in exactly one line.

69. A, B, and D

70. Post. 1-1: Through any two points there is exactly one line.

59.

yes

60. always

61. never

62. always

63. always

64. sometimes

65. never

66. a. 1b. 1c. 1d. 1e. A line and a point not on the line are always coplanar.

67.

Post. 1-4: Through three noncollinear points there is exactly one plane.

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Page 26: Geo chapter01power point

71. Post. 1-3: If two planes intersect, then they intersect in exactly one line.

72. The end of one leg might not be coplanar with the ends of the other three legs. (Post. 1-4)

73.

yes

Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1–2GEOMETRY LESSON 1–2

76.

no

77.

yes

74.

yes

75.

no

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Page 27: Geo chapter01power point

Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1–2GEOMETRY LESSON 1–2

81. a. Since the plane is flat, the line would have to curve so as to contain the 2 points and not lie in the plane; but lines are straight.

b. One plane; Points A, B, and C are

noncollinear. By Post. 1-4, they

are coplanar.Then, by part

(a), AB and BC are coplanar.

82. 1

78.

no

79. Infinitely many; explanations may vary. Sample: Infinitely many planes can intersect in one line.

80.

By Post. 1-1, points D and B determine a line and points A and D determine a line. The distress signal is on both lines and, by Post. 1-2, there can be only one distress signal.

1-2

Page 28: Geo chapter01power point

Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1–2GEOMETRY LESSON 1–2

94. 25, -5

95. 34

96. 44

83.

84. 1

85. A

86. I

87. B

88. H

89. [2] a. ABD, ABC, ACD, BCD

b. AD, BD, CD[1] one part correct

90.

91. I, K

92. 42, 56

93. 1024, 4096

14

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Page 29: Geo chapter01power point

Points, Lines, and PlanesPoints, Lines, and PlanesGEOMETRY LESSON 1-2GEOMETRY LESSON 1-2

1. Name three collinear points.

2. Name two different planes that contain points C and G.

3. Name the intersection of plane AED and plane HEG.

4. How many planes contain the points A, F, and H?

5. Show that this conjecture is false by finding one counterexample: Two planes always intersect in exactly one line.

Use the diagram at right.

D, J, and H

planes BCGF and CGHD

HE

1

Sample: Planes AEHD and BFGC never intersect.

1-2

Page 30: Geo chapter01power point

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and Planes

(For help, go to Lesson 1-2.)

Judging by appearances, will the lines intersect?

1. 2. 3.

Name the plane represented by each surface  of the box.

4. the bottom 5. the top

6. the front 7. the back

8. the left side 9. the right side

GEOMETRY LESSON 1-3GEOMETRY LESSON 1-3

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Page 31: Geo chapter01power point

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and Planes

1. no 2. yes 3. no

4. NMR 5. PQL 6. NKL

7. PQR 8. PKN 9. LQR

GEOMETRY LESSON 1-3GEOMETRY LESSON 1-3

Solutions

1-3

Page 32: Geo chapter01power point

Name the segments and rays in the figure.

The labeled points in the figure are A, B, and C.

A segment is a part of a line consisting of two endpoints and all points between them. A segment is named by its two endpoints. So the segments are BA (or AB) and BC (or CB).

A ray is a part of a line consisting of one endpoint and all the points of the line on one side of that endpoint. A ray is named by its endpoint first, followed by any other point on the ray. So the rays areBA and BC.

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and PlanesGEOMETRY LESSON 1-3GEOMETRY LESSON 1-3

1-3

Page 33: Geo chapter01power point

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and PlanesGEOMETRY LESSON 1-3GEOMETRY LESSON 1-3

Use the figure below. Name all segments that

are parallel to AE. Name all segments that are skew to AE.

Parallel segments lie in the same plane, and the lines that contain them do not intersect. The three segments in the figure above that are parallel to AE are BF, CG, and DH.

Skew lines are lines that do not lie in the same plane. The four lines in the figure that do not lie in the same plane as are AE, BC, CD, and GH.

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Page 34: Geo chapter01power point

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and Planes

Planes are parallel if they do not intersect. If the walls of your classroom are vertical, opposite walls are parts of parallel planes. If the ceiling and floor of the classroom are level, they are parts of parallel planes.

Identify a pair of parallel planes in your classroom.

GEOMETRY LESSON 1-3GEOMETRY LESSON 1-3

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Page 35: Geo chapter01power point

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and PlanesGEOMETRY LESSON 1–3GEOMETRY LESSON 1–3

12. BC

13. BE, CF

14. DE, EF, BE

15. AD, AB, AC

16. BC, EF

17. ABC || DEF

1.

2.

3.

4.

5. RS, RT, RW, ST, SW, TW

6. RS, ST, TW, WT, TS, SR

7. a. TS or TR, TWb. SR, ST

8. 4; RY, SY, TY, WY

9. Answers may vary.Sample: 2; YS or YR, YT or YW

10. Answers may vary.Check students’ work.

11. DF

Pages 19-22 Practice and Problem Solving

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Page 36: Geo chapter01power point

25. true

26. False; they are skew.

27. true

28. False; they intersect above CG.

29. true

30. False; they intersect above pt. A.

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and PlanesGEOMETRY LESSON 1–3GEOMETRY LESSON 1–3

31. False; they are ||.

32. False; they are ||.

33. Yes; both name the segment with endpoints X and Y.

34. No; the two rays have different endpoints.

35. Yes; both are the line through pts. X and Y.

18. BE || AD

19. CF, DE

20. DEF, BC

21. FG

22. Answers may vary. Sample: CD, AB

23. BG, DH, CL

24. AF

Pages 18-20 Answers may vary. Samples are given

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Page 37: Geo chapter01power point

Pages 19-22 Exercises

36.

37. always

38. never

39. always

40. always

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and PlanesGEOMETRY LESSON 1–3GEOMETRY LESSON 1–3

41. never

42. sometimes

43. always

44. sometimes

45. always

46. sometimes

47. sometimes

48. Answers may vary. Sample: (0, 0); check students’ graphs.

49. a. Answers may vary. Sample: northeast

and southwestb. Answers may vary. Sample: northwest

and southeast, east and west

50. Two lines can be parallel, skew, or intersecting in one point. Sample: train tracks–parallel; vapor trail of a northbound jet and an eastbound jet at different altitudes– skew; streets that cross–intersecting

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Page 38: Geo chapter01power point

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and PlanesGEOMETRY LESSON 1–3GEOMETRY LESSON 1–3

55. a. The lines of intersection

are parallel.

b. Examples may vary. Sample: The floor and ceiling are parallel. A wall

intersects both. The lines of intersection

are parallel.

56. Answers may vary. Sample: The diamond structure makes it tough, strong, hard, and durable. The graphite structure makes it soft and slippery.

57. a.

one segment; EF

b.

3 segments; EF, EG, FG

51. Answers may vary. Sample: Skew lines cannot be contained in one plane. Therefore, they have “escaped” a plane.

52. ST || UV

53. Answers may vary.Sample: XY and ZWintersect in R.

54. Planes ABC and DCBFintersect in BC.

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Page 39: Geo chapter01power point

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and PlanesGEOMETRY LESSON 1–3GEOMETRY LESSON 1–3

58. No; two different planes cannot intersect in more than one line.

59. yes; plane P, for example

60. Answers may vary.Sample: VR, QR, SR

61. QR

62. Yes; no; yes; explanations may vary.

63. D

64. H

65. B

66. F

67. B

68. C

69. D

57. c.

Answers may vary. Sample: For each “new” point, the number of new segments equals the number of “old” points.d. 45 segments

e. n(n - 1)2

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Page 40: Geo chapter01power point

79.

80.

81.

82. 1.4, 1.48

83. –22, –29

84. FG, GH

85. P, S

86. No; whenever you subtract a negative number, the answer is greater than the given number. Also, if you subtract 0, the answer stays the same.

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and PlanesGEOMETRY LESSON 1–3GEOMETRY LESSON 1–3

71–78. Answers may vary. Samples are

given.

71. EF

72. A

73. C

74. AEF and HEF

75. ABH

76. EHG

77. FG

78. B

70. [2] a. Alike: They do not intersect.

Different: Parallel lines are coplanar

and skew lines lie in different

planes.

b. No; of the 8 other lines shown, 4 intersect

JM and 4 are skew

to JM.

[1] one likeness, one difference

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Page 41: Geo chapter01power point

Segments, Rays, Parallel Lines and PlanesSegments, Rays, Parallel Lines and PlanesGEOMETRY LESSON 1-3GEOMETRY LESSON 1-3

Use the figure below for Exercises 1-3.

1. Name the segments that form the triangle. 2. Name the rays that have point T as their endpoint.

3. Explain how you can tell that no lines in the figure are parallel or skew.

Use the figure below for Exercises 4 and 5.

4. Name a pair of parallel planes.

5. Name a line that is skew to XW.

TO, TP, TR, TS

The three pairs of lines intersect, So they cannot be parallel or skew.

AC or BD

RS, TR, ST plane BCD || plane XWQ

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Page 42: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and Angles

(For help, go to the Skills Handbook pages 719 and 720.)

Simplify each absolute value expression.

1. |–6| 2. |3.5| 3. |7 – 10|

4. |–4 – 2| 5. |–2 – (–4)| 6. |–3 + 12|

Solve each equation.

7. x + 2x – 6 = 6

8. 3x + 9 + 5x = 81

9. w – 2 = –4 + 7w

1-4

GEOMETRY LESSON 1-4GEOMETRY LESSON 1-4

Page 43: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and Angles

1. The number of units from 0 to –6 on the number line is 6.

2. The number of units from 0 to 3.5 on the number line is 3.5.

3. |7 – 10| = |–3|, and the number of units from 0 to –3 on the number line is 3.

4. |–4 – 2| = |–6|, and the number of units from 0 to –6 on the number line is 6.

5. |–2 – (–4)| = |–2 + 4| = |2|, and the number of units from 0 to 2 on the

number line is 2.

6. |–3 + 12| = |9|, and the number of units from 0 to 9 on the number line is 9.

7. Combine like terms: 3x – 6 = 6; add 6: 3x = 12; divide by 3: x = 4

8. Combine like terms: 8x + 9 = 81; subtract 9: 8x = 72; divide by 8: x = 9

9. Add –7w + 2: –6w = –2; divide by –6: w = 13

GEOMETRY LESSON 1-4GEOMETRY LESSON 1-4

Solutions

1-4

Page 44: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and Angles

Use the Ruler Postulate to find the length of each segment.

XY = | –5 – (–1)| = | –4| = 4

ZY = | 2 – (–1)| = |3| = 3

ZW = | 2 – 6| = |–4| = 4

Find which two of the segments XY, ZY, and ZW

are congruent.

GEOMETRY LESSON 1-4GEOMETRY LESSON 1-4

Because XY = ZW, XY ZW.

1-4

Page 45: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and AnglesGEOMETRY LESSON 1-4GEOMETRY LESSON 1-4

Use the Segment Addition Postulate to write an equation.

AN + NB = AB Segment Addition Postulate(2x – 6) + (x + 7) = 25 Substitute.

3x + 1 = 25 Simplify the left side. 3x = 24 Subtract 1 from each side. x = 8 Divide each side by 3.

AN = 10 and NB = 15, which checks because the sum of the segment lengths equals 25.

If AB = 25, find the value of x. Then find AN and NB.

AN = 2x – 6 = 2(8) – 6 = 10 NB = x + 7 = (8) + 7 = 15

Substitute 8 for x.

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Page 46: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and AnglesGEOMETRY LESSON 1-4GEOMETRY LESSON 1-4

Use the definition of midpoint to write an equation.

RM = MT Definition of midpoint5x + 9 = 8x – 36 Substitute.

5x + 45 = 8x Add 36 to each side. 45 = 3x Subtract 5x from each side. 15 = x Divide each side by 3.

RM and MT are each 84, which is half of 168, the length of RT.

M is the midpoint of RT. Find RM, MT, and RT.

RM = 5x + 9 = 5(15) + 9 = 84MT = 8x – 36 = 8(15) – 36 = 84

Substitute 15 for x.

RT = RM + MT = 168

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Page 47: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and AnglesGEOMETRY LESSON 1-4GEOMETRY LESSON 1-4

Name the angle below in four ways.

The name can be the vertex of the angle: G.

Finally, the name can be a point on one side, the vertex, and a point on the other side of the angle: AGC, CGA.

The name can be the number between the sides of the angle: 3.

1-4

Page 48: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and Angles

Because 0 < 80 < 90, 2 is acute.

m 2 = 80

Use a protractor to measure each angle.m 1 = 110

Because 90 < 110 < 180, 1 is obtuse.

Find the measure of each angle. Classify each as acute, right,

obtuse, or straight.

GEOMETRY LESSON 1-4GEOMETRY LESSON 1-4

1-4

Page 49: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and Angles

Use the Angle Addition Postulate to solve.

m 1 + m 2 = m ABC Angle Addition Postulate.

42 + m 2 = 88 Substitute 42 for m 1 and 88 for m ABC.

m 2 = 46 Subtract 42 from each side.

Suppose that m 1 = 42 and m ABC =88. Find m 2.

GEOMETRY LESSON 1-4GEOMETRY LESSON 1-4

1-4

Page 50: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and AnglesGEOMETRY LESSON 1–4GEOMETRY LESSON 1–4

15. 130

16. XYZ, ZYX, Y

17. MCP, PCM, C or 1

18. ABC, CBA

19. CBD, DBC

9. 25

10. a. 13b. RS = 40, ST = 24

11. a. 7b. RS = 60, ST = 36, RT = 96

12. a. 9b. 9; 18

13. 33

14. 34

1. 9; 9; yes

2. 9; 6; no

3. 11; 13; no

4. 7; 6; no

5. XY = ZW

6. ZX = WY

7. YZ < XW

8. 24

pages 29–33  Practice and Problem Solving

1-4

Page 51: Geo chapter01power point

20-23. Drawings may vary.

20.

21.

22.

23.

Measuring Segments and AnglesMeasuring Segments and AnglesGEOMETRY LESSON 1–4GEOMETRY LESSON 1–4

33. –2.5, 2.5

34. –3.5, 3.5

35. –6, –1, 1, 6

36. a. 78 mib. Answers may vary. Sample: measuring

with a ruler

37–41. Check students’ work.

24. 60; acute

25. 90; right

26. 135; obtuse

27. 34

28. 70

29. Q

30. 6

31. –4

32. 1

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Page 52: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and AnglesGEOMETRY LESSON 1–4GEOMETRY LESSON 1–4

60. 150

61. 30

62. 100

63. 40

64. 80

65. 125

66. 125

49. Answers may vary. Sample: (15, 0), (–9, 0), (3, 12), (3, –12)

50–54. Check students’ work.

55. about 42°

56–58. Answers may vary. Samples are given.

56. 3:00, 9:00

57. 5:00, 7:00

58. 6:00, 12:32

59. 180

42. true; AB = 2, CD = 2

43. false; BD = 9, CD = 2

44. false; AC = 9, BD = 9, AD = 11, and 9 + 9 ≠ 11

45. true; AC = 9, CD = 2, AD = 11, and 9 + 2 = 11

46. 2, 12

47. 115

48. 65

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Page 53: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and AnglesGEOMETRY LESSON 1–4GEOMETRY LESSON 1–4

75. 12; m AOC = 82,m AOB = 32,m BOC = 50

76. 8; m AOB = 30,m BOC = 50,m COD = 30

77. 18; m AOB = 28,m BOC = 52,m AOD = 108

78. 7; m AOB = 28,m BOC = 49,m AOD = 111

79. 30

71. y = 15; AC = 24, DC = 12

72. ED = 10, DB = 10, EB = 20

73. a. Answers may vary. Sample: The two rays come together at a sharp point.b. Answers may vary. Sample: Molly had an acute pain in her knee.

74. 45, 75, and 165, or 135, 105, and 15

67–68. Answers may vary. Samples are

given

67. QVM and VPN

68. MNP and MVN

69. MQV and PNQ

70. a. 19.5b. 43; 137c. Answers may

vary. Sample: The sum of the

measures should be 180.

1-4

Page 54: Geo chapter01power point

86. [2] a.

b. An obtuse measures between 90 and 180 degrees; the least and greatest whole number values are 91 and 179 degrees. Part of

ABC is 12°. So the least and greatest measures

for DBC are 79 and 167.

[1] one part correct

Measuring Segments and AnglesMeasuring Segments and AnglesGEOMETRY LESSON 1–4GEOMETRY LESSON 1–4

87. never

88. never

89. always

90. never

91. always

92. always

93. always

94. never

95. 25, 30

96. 3125; 15,625

97. 30, 34

80. a–c. Check students’ work.

81. Angle Add. Post.

82. C

83. F

84. D

85. H

1-4

Page 55: Geo chapter01power point

Measuring Segments and AnglesMeasuring Segments and AnglesGEOMETRY LESSON 1-4GEOMETRY LESSON 1-4

Use the figure below for Exercises 4–6.

4. Name 2 two different ways.

5. Measure and classify 1, 2, and BAC.

6. Which postulate relates the measures of 1, 2, and BAC?

14Angle Addition Postulate

DAB, BAD

Use the figure below for Exercises 1-3.

1. If XT = 12 and XZ = 21, then TZ = 7.

2. If XZ = 3x, XT = x + 3, and TZ = 13, find XZ.

3. Suppose that T is the midpoint of XZ. If XT = 2x + 11 and XZ = 5x + 8, find the value of x.

9

24 90°, right; 30°, acute; 120°, obtuse

1-4

Page 56: Geo chapter01power point

Basic ConstructionBasic Construction

In Exercises 1-6, sketch each figure.

1. CD 2. GH 3. AB

4. line m 5. acute ABC 6. XY || ST

7. DE = 20. Point C is the midpoint of DE. Find CE.

8. Use a protractor to draw a 60° angle.

9. Use a protractor to draw a 120° angle.

(For help, go to Lesson 1-3 and 1-4.)

GEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

1-5

Page 57: Geo chapter01power point

Basic ConstructionBasic Construction

1. The figure is a segment whose endpoints are C and D.

2. The figure is a ray whose endpoint is G.

3. The figure is a line going through the points A and B.

4. 5. The figure is an angle whose

measure is between 0° and 90°.

6. The figure is two segments in a plane whose corresponding  

lines do not intersect.

7. Since C is a midpoint, CD = CE; also, CD + CE = 20;

substituting results in CE + CE = 20, or 2CE = 20, so CE = 10.

8. 9.

GEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

Solutions

1-5

Page 58: Geo chapter01power point

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

Step 2: Open the compass to the length of KM.

Construct TW congruent to KM.

Step 1: Draw a ray with endpoint T.

Step 3: With the same compass setting, put the compass point on point T. Draw an arc that intersects the ray. Label the point of intersection W.

TW KM

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Page 59: Geo chapter01power point

Basic ConstructionBasic Construction

~

Step 3: With the same compass setting, put the compass point on point Y. Draw an arc that intersects the ray. Label the point of intersection Z.

Construct Y so that Y = G.

Step 1: Draw a ray with endpoint Y.

Step 2: With the compass point on point G, draw an arc that intersects both sides of G. Label the points of intersection E and F.

GEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

1-5

Page 60: Geo chapter01power point

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

(continued)

Step 4: Open the compass to the length EF. Keeping the same compass setting, put the compass point on Z. Draw an arc that intersects the arc you drew in Step 3. Label the point of intersection X.

Step 5: Draw to complete Y.

Y G

1-5

Page 61: Geo chapter01power point

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

Step 1: Put the compass point on

point A and draw a short arc. Make

sure that the opening is less than AB.12

Start with AB.

Step 2: With the same compass setting, put the compass point on point B and draw a short arc.

Without two points of intersection, no line can be drawn, so the perpendicular bisector cannot be drawn.

Use a compass opening less than AB. Explain why the

construction of the perpendicular bisector of AB is not possible.

12

1-5

Page 62: Geo chapter01power point

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

–3x = –48 Subtract 4x from each side. x = 16 Divide each side by –3.

m AWR = m BWR Definition of angle bisector x = 4x – 48 Substitute x for m AWR and

4x – 48 for m BWR.

m AWB = m AWR + m BWR Angle Addition Postulatem AWB = 16 + 16 = 32 Substitute 16 for m AWR and

for m BWR.

Draw and label a figure to illustrate the problem

WR bisects AWB. m AWR = x and m BWR = 4x – 48. Find m AWB.

m AWR = 16 m BWR = 4(16) – 48 = 16 Substitute 16 for x.

1-5

Page 63: Geo chapter01power point

Basic ConstructionBasic Construction

Step 1: Put the compass point on vertex M. Draw an arc that intersects both sides of M. Label the points of intersection B and C.

Step 2: Put the compass point on point B. Draw an arc in the interior of M.

Construct MX, the bisector of M.

GEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

1-5

Page 64: Geo chapter01power point

Basic ConstructionBasic Construction

Step 4: Draw MX. MX is the angle bisector of M.

(continued)

Step 3: Put the compass point on point C. Using the same compass setting, draw an arc in the interior of M. Make sure that the arcs intersect. Label the point where the two arcs intersect X.

GEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

1-5

Page 65: Geo chapter01power point

6.

7.

8.

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1–5GEOMETRY LESSON 1–5

9. a. 11; 30b. 30c. 60

10. 5; 50

11. 15; 48

12. 11; 56

13.

1.

2.

3.

4.

5.

1-5

Page 66: Geo chapter01power point

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1–5GEOMETRY LESSON 1–5

16. Find a segment on XY so that you can construct YZ as its bisector.

17. Find a segment on SQ so that you can construct SP as its bisector. Then bisect PSQ.

18. a. CBD; 41b. 82c. 49; 49

19. a-b.

14.

15.

1-5

Page 67: Geo chapter01power point

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1–5GEOMETRY LESSON 1–5

21. Explanations may vary. Samples are given.a. One midpt.; a midpt.

divides a segment into two segments. If there were more than one

midpt. the segments wouldn’t be .

b. Infinitely many; there’s only 1 midpt. but there exist infinitely many lines through the midpt. A

segment has exactly one bisecting line because there can be only one line to a segment at its midpt.

c. There are an infinite number of lines in space that are to a

segment at its midpt. The

lines are coplanar.

20. Locate points A and B on a line. Then construct a at A and B as in Exercise 16.Construct AD and BCso that AB = AD = BC.

1-5

Page 68: Geo chapter01power point

27.

28. a.

They appear to meet at one

pt.

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1–5GEOMETRY LESSON 1–5

25. They are both correct. If you mult. each side of Lani’s eq. by 2, the result is Denyse’s eq.

26. Open the compass to more than half the measure of the segment. Swing large arcs from the endpts. to intersect above and below the segment. Draw a line through the two pts. where the arcs intersect. The pt. where the line and segment intersect is the midpt. of the segment.

22.

23.

24.

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Page 69: Geo chapter01power point

33. a.

b. They are all 60°.c. Answers may vary. Sample: Mark a pt., A. Swing a long arc from A. From a pt. P on the arc, swing

another arc the same size that intersects the

arc at a second pt., Q. Draw PAQ.

To construct a 30° , bisect the 60° .

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1–5GEOMETRY LESSON 1–5

30.

31. impossible; the short segments are not long enough to form a .

32. impossible; the short segments are not long enough to form a .

b.

c. The three bisectors of a

intersect in one pt.

29.

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Page 70: Geo chapter01power point

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1–5GEOMETRY LESSON 1–5

Label the intersection K.

Open the compass to PQ.

With compass pt. on K,

swing an arc to intersect

the first arc. Label the

intersection R. Draw XR.

c. Point O is the center of the circle.

36. ; the line intersects.

37. D

38. F

39. [2] a. Draw XY. With the

compass pt. on B

swing an arc that

intersects BA and

BC. Label the

intersections

P and Q, respectively.

With the compass

point on X, swing a

arc intersecting XY.

34. a-c.

35. a-c.

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Page 71: Geo chapter01power point

41. 642. 1043. 444. 345.

46. 10047. 20 and 18048.

49. No; they do not have

the same endpt.50. Yes; they both

represent a segment with endpts. R and S.

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1–5GEOMETRY LESSON 1–5

39. [2] b. With compass open to XK, put compass point on X and swing an arc intersecting XR. With compass on R and open to KR, swing

an arc to intersect the first arc. Label intersection T. Draw XT.

[1] one part correct40. [4] a. Construct its

bisector.b. Construct the

bisector. Then construct the bisector of two new

segments.

c. Draw AB. Do constructions as in

parts a and b. Open the compass to the

length of the shortest segment in part b.

With the pt. of the compass on B,

swing an arc in the opp. direction from A

intersecting AB at C. AC = 1.25 (AB).

[3] explanations are not thorough

[2] two explanations correct[1] part (a) correct

1-5

Page 72: Geo chapter01power point

Basic ConstructionBasic ConstructionGEOMETRY LESSON 1-5GEOMETRY LESSON 1-5

For problems 1-4, check students’ work.

QN bisects DNB.

1. Construct AC so that AC NB.

2. Construct the perpendicular bisector of AC.

3. Construct RST so that RST QNB.

4. Construct the bisector of RST.

5. Find x.

6. Find m DNB. 88

Use the figure at right.

17

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Page 73: Geo chapter01power point

The Coordinate PlaneThe Coordinate Plane

(For help, go to the Skills Handbook pages 715 and 716.)

GEOMETRY LESSON 1-6GEOMETRY LESSON 1-6

1-6

Find the square root of each number to the nearest tenth. Use a calculator if necessary.

1. 25 2. 17 3. 123

Evaluate each expression for m = –3 and n = 7.

4. (m – n)2 5. (n – m)2 6. m2 + n2

Evaluate each expression for a = 6 and b = –8.

7. (a – b)2 8. 9.a2 + b2 a + b2

Page 74: Geo chapter01power point

The Coordinate PlaneThe Coordinate PlaneGEOMETRY LESSON 1-6GEOMETRY LESSON 1-6

Solutions

1. 25 = 52 = 5 2. 17 4.1232 = 4.123

3. 123 11.092 = 11.09

4. (m – n)2 = (–3 –7)2

= (–10)2

= 100

5. (n – m)2 = –7 – (–3))2

= (7 + 3)2

=102 = 100

6. m2 + n2 = (–3)2 + (7)2

= 9 + 49= 58

7. (a – b)2 = (6 – (–8))2

= (6 + 8)2

=142 = 196

8. a2 + b2 = (6)2 + (–8)2

= 36 + 64= 100 = 10

9.

–22= = –1

a + b2

6 + (–8)2=

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Page 75: Geo chapter01power point

d = 82 + (–8)2 Simplify.

The Coordinate PlaneThe Coordinate Plane

Find the distance between R(–2, –6) and S(6, –2)

to the nearest tenth.

Let (x1, y1) be the point R(–2, –6) and (x2, y2) be the point S(6, –2).

To the nearest tenth, RS = 11.3.

128 11.3137085 Use a calculator.

GEOMETRY LESSON 1-6GEOMETRY LESSON 1-6

d = (x2 – x1)2 + (y2 – y1)2 Use the Distance Formula.

d = (6 – (–2))2 + (–2 – (–6))2 Substitute.

d = 64 + 64 = 128

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Page 76: Geo chapter01power point

The Coordinate PlaneThe Coordinate Plane

Oak has coordinates (–1, –2). Let (x1, y1) represent Oak. Symphony has coordinates (1, 2). Let (x2, y2) represent Symphony.

To the nearest tenth, the subway ride from Oak to Symphony is 4.5 miles.

20 4.472135955 Use a calculator.

GEOMETRY LESSON 1-6GEOMETRY LESSON 1-6

d = 22 + 42 Simplify.

d = (x2 – x1)2 + (y2 – y1)2 Use the Distance Formula.

How far is the subway ride from Oak to

Symphony? Round to the nearest tenth.

d = (1 – (–1))2 + (2 – (–2))2 Substitute.

d = 4 + 16 = 20

1-6

Page 77: Geo chapter01power point

The Coordinate PlaneThe Coordinate PlaneGEOMETRY LESSON 1-6GEOMETRY LESSON 1-6

Use the Midpoint Formula. Let (x1, y1) be A(8, 9) and (x2, y2) be B(–6, –3).

The coordinates of midpoint M are (1, 3).

AB has endpoints (8, 9) and (–6, –3). Find the coordinates of

its midpoint M.

The midpoint has coordinates Midpoint Formula

( , )x1 + x2

2

y1 + y2

2

Substitute 8 for x1 and (–6) for x2. Simplify.

8 + (–6)2The x–coordinate is = = 1

22

Substitute 9 for y1 and (–3) for y2. Simplify.

9 + (–3)2The y–coordinate is = = 3

62

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Page 78: Geo chapter01power point

The Coordinate PlaneThe Coordinate PlaneGEOMETRY LESSON 1-6GEOMETRY LESSON 1-6

Find the x–coordinate of G. Find the y–coordinate of G.

4 + y2

25 =

1 + x2

2–1 = Use the Midpoint Formula.

The coordinates of G are (–3, 6).

The midpoint of DG is M(–1, 5). One endpoint is D(1, 4). Find

the coordinates of the other endpoint G.

–2 = 1 + x2 10 = 4 + y2Multiply each side by 2.

Use the Midpoint Formula. Let (x1, y1) be D(1, 4) and the midpoint

be (–1, 5). Solve for x2 and y2, the coordinates of G.( , )x1 + x2

2

y1 + y2

2

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Page 79: Geo chapter01power point

The Coordinate PlaneThe Coordinate PlaneGEOMETRY LESSON 1–6GEOMETRY LESSON 1–6

11. about 4.5 mi

12. about 3.2 mi

13. 6.4

14. 15.8

15. 15.8

16. 5

17. B, C, D, E, F

18. (4, 2)

19. (3, 1)

20. (3.5, 1)

21. (6, 1)

22. (–2.25, 2.1)

23. (3 , –3)

24. (10, –20)

25. (5, –1)

26. (0, –34)

27. (12, –24)

28. (9, –28)

29. (5.5, –13.5)

30. (8, 18)

31. (4, –11)

1. 6

2. 18

3. 8

4. 9

5. 23.3

6. 10

7. 25

8. 12.2

9. 12.0

10. 9 mi

pages 46–48  Practice and Problem Solving

78

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Page 80: Geo chapter01power point

The Coordinate PlaneThe Coordinate PlaneGEOMETRY LESSON 1–6GEOMETRY LESSON 1–6

41. IV

42.

The midpts. Are the same, (5, 4). The diagonals bisect each other.

32. 5.0; (4.5, 4)

33. 5.8; (1.5, 0.5)

34. 7.1; (–1.5, 0.5)

35. 5.4; (–2.5, 3)

36. 10; (1, –4)

37. 2.8; (–4, –4)

38. 6.7; (–2.5, –2)

39. 5.4; (3, 0.5)

40. 2.2; (3.5, 1)

43.

ST = (5 – 2)2 + (–3 – (–6))2 = 9 + 9 = 3 2 4.2TV = (6 – 5)2 + (–6 – (–3))2 = 1 + 9 = 10 3.2SW = (5 – 6)2 + (–9 – (–6))2 = 9 + 9 = 3 2 4.2

No, but ST = SW and TV = VW.

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Page 81: Geo chapter01power point

The Coordinate PlaneThe Coordinate PlaneGEOMETRY LESSON 1–6GEOMETRY LESSON 1–6

50. 1073 mi

51. 2693 mi

52. 328 mi

53–56. Answers may vary. Samples are

given.

53. (3, 6), (0, 4.5)

54. E (0, 0), (8, 4)

55. (1, 0), (–1, 4)

56. (0, 10), (5, 0)

44. 19.2 units; (–1.5, 0)

45. 10.8 units; (3, –4)

46. 5.4 units; (–1, 0.5)

47. Z; about 12 units

48. 165 units; The dist. TV is less than the dist. TU, so the airplane should fly from T to V to U for the shortest route.

49. 934 mi

57. exactly one pt., E (–5, 2)

58. exactly one pt., J (2, –2)

59. a–f. Answers may vary. Samples are given.

a. BC = AD

b. If two opp. sides of a quad. are both || and , then the other two opp. sides are .

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Page 82: Geo chapter01power point

The Coordinate PlaneThe Coordinate PlaneGEOMETRY LESSON 1–6GEOMETRY LESSON 1–6

f. If a pair of opp. sides of a

quad. are both || and , then

the segment joining the midpts. of the

other two sides has the same length as

each of the first pair of sides.

60. A (0, 0, 0)B (6, 0, 0)C (6, –3.5, 0)D (0, –3.5, 0)E (0, 0, 9)F (6, 0, 9)G (0, –3.5, 9)

c. The midpts. are the same.

d. If one pair of opp. sides of a quad. are both || and , then its diagonals bisect each other.

e. EF = AB

61.

62. 6.5 units

63. 11.7 units

64. B

65. I

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Page 83: Geo chapter01power point

66. A

67. C

68. A

69. [2] a. (–10, 8), (–1, 5), (8, 2)

b. Yes, R must

be (–10,

8) so that

RQ = 160.

[1] part (a) correct or plausible

explanation for part (b)

The Coordinate PlaneThe Coordinate PlaneGEOMETRY LESSON 1–6GEOMETRY LESSON 1–6

70.

71.

72.

73.

74. 10

75. 10

76. 48

77. TAP, PAT

78. 150

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Page 84: Geo chapter01power point

The Coordinate PlaneThe Coordinate PlaneGEOMETRY LESSON 1-6GEOMETRY LESSON 1-6

1. Find the distance between A and B to the nearest tenth.

2. Find BC to the nearest tenth.

3. Find the midpoint M of AC to the nearest tenth.

4. B is the midpoint of AD. Find the coordinates of endpoint D.

5. An airplane flies from Stanton to Mercury in a straight flight path. Mercury is 300 miles east and 400 miles south of Stanton. How many miles is the flight?

6. Toni rides 2 miles north, then 5 miles west, and then 14 miles south. At the end of her ride, how far is Toni from her starting point, measured in a straight line? 13 mi

A has coordinates (3, 8). B has coordinates (0, –4). C has coordinates (–5, –6).

12.4

5.4

(–1, 1)

(–3, –16)

500 mi

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Page 85: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and Area

(For help, go to the Skills Handbook page 719 and Lesson 1-6.)

Simplify each absolute value.

1. |4 – 8| 2. |10 – (–5)| 3. |–2 – 6|

Find the distance between the points to the nearest tenth.

4. A(2, 3), B(5, 9) 5. K(–1, –3), L(0, 0)

6. W(4, –7), Z(10, –2) 7. C(–5, 2), D(–7, 6)

8. M(–1, –10), P(–12, –3) 9. Q(–8, –4), R(–3, –10)

GEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

1-7

Page 86: Geo chapter01power point

4. d = (x2 – x1)2 + (y2 – y1)2

d = (5 – 2)2 + (9 – 3)2

d = 32 + 62

d = 9 + 36 = 45

To the nearest tenth, AB = 6.7.

6. d = (x2 – x1)2 + (y2 – y1)2

d = (10 – 4)2 + ( – 2 –(– 7))2

d = 62 + 52

d = 36 + 25 = 61

To the nearest tenth, WZ = 7.8.

2. | 10 – (–5) | = | 10 + 5 | = | 15 | = 15

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

1. | 4 – 8 | = | –4 | = 4

Solutions

3. | –2 – 6 | = | –8 | = 8

5. d = (x2 – x1)2 + (y2 – y1)2

d = (0 – (–1))2 + (0 – (–3))2

d = 12 + 32

d = 1 + 9 = 10

To the nearest tenth, KL = 3.2.

7. d = (x2 – x1)2 + (y2 – y1)2

d = (– 7 – (– 5))2 + (6 – 2)2

d = (–2)2 + 52

d = 4 + 16 = 20

To the nearest tenth, CD = 4.5.

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Page 87: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

Solutions (continued)

8.

9.

d = (x2 – x1)2 + (y2 – y1)2

d = (–12 – (–1))2 + (–3 – (–10))2

d = (–11)2 + 72

d = 121 + 49 = 170

To the nearest tenth, MP = 13.0.

d = (x2 – x1)2 + (y2 – y1)2

d = (–3 – (–8))2 + (–10 – (–4))2

d = 52 + (–6)2

d = 25 + 36 = 61

To the nearest tenth, QR = 7.8.

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Page 88: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and Area

Margaret’s garden is a square 12 ft on each side.

Margaret wants a path 1 ft wide around the entire garden.

What will the outside perimeter of the path be?

The perimeter is 56 ft.

P = 4s Formula for perimeter of a square

P = 4(14) = 56 Substitute 14 for s.

GEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

Because the path is 1 ft wide, increase each side of the garden by 1 ft. s = 1 + 12 + 1 = 14

1-7

Page 89: Geo chapter01power point

C = 2 (6.5) Substitute 6.5 for r.

The circumference of G is 13 , or about 40.8 cm..

Perimeter, Circumference, and AreaPerimeter, Circumference, and Area

C = 13 Exact answer.

C = 13 40.840704 Use a calculator.

GEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

C = 2 r Formula for circumference of a circle.

G has a radius of 6.5 cm. Find the circumference of G in

terms of . Then find the circumference to the nearest tenth.

. .

1-7

Page 90: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

Quadrilateral ABCD has vertices

A(0, 0), B(9, 12), C(11, 12), and D(2, 0).

Find the perimeter.

Draw and label ABCD on a coordinate plane.

BC = |11 – 9| = |2| = 2 Ruler Postulate

DA = |2 – 0| = |2| = 2 Ruler Postulate

Find the length of each side. Add the lengths to find the perimeter.

AB = (9 – 0)2 + (12 – 0)2 = 92 + 122 Use the Distance Formula.

= 81 + 144 = 255 = 15

CD = (2 – 11)2 + (0 – 12)2 = (–9)2 + (–12)2 Use the Distance Formula.

= 81 + 144 = 255 = 15

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Page 91: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and Area

(continued)

Perimeter = AB + BC + CD + DA

= 15 + 2 + 15 + 2

= 34

The perimeter of quadrilateral ABCD is 34 units.

GEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

1-7

Page 92: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and Area

Write both dimensions using the same unit of measurement. Find the area of the rectangle using the formula A = bh.

36 in. = 3 ft Change inches to feet using 12 in. = 1 ft.

A = bh Formula for area of a rectangle.

A = (4)(3) Substitute 4 for b and 3 for h.

A = 12

You need 12 ft2 of fabric.

To make a project, you need a rectangular piece of fabric 36 in. wide and 4 ft long. How many square feet of fabric do you need?

GEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

1-7

Page 93: Geo chapter01power point

A = r2 Formula for area of a circle

A = (1.5)2 Substitute 1.5 for r.

A = 2.25

Perimeter, Circumference, and AreaPerimeter, Circumference, and Area

In B, r = 1.5 yd..

The area of B is 2.25 yd2..

GEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

Find the area of B in terms of . .

1-7

Page 94: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

Find the area of the figure below.

Draw a horizontal line to separate the figure into three nonoverlapping figures: a rectangle and two squares.

1-7

Page 95: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

AR = bh Formula for area of a rectangleAR = (15)(5) Substitute 15 for b and 5 for h.AR = 75

AS = s2 Formula for area of a squareAS = (5)2 Substitute 5 for s.AS = 25

A = 75 + 25 + 25 Add the areas. A = 125

The area of the figure is 125 ft2.

Find each area. Then add the areas.

(continued)

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Page 96: Geo chapter01power point

1. 22 in.

2. 36 cm

3. 56 in.

4. 78 cm

5. 120 m

6. 48 in.

7. 38 ft

8. 15 cm

9. 10 ft

10. 3.7 in.

11. m

12. 56.5 in.

13. 22.9 m

14. 1.6 yd

15. 351.9 cm

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1–7GEOMETRY LESSON 1–7

16.

14.6 units17.

25.1 units

pages 55–58  Practice and Problem Solving

12

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Page 97: Geo chapter01power point

29. in.2

30. 0.25 m2

31. 9.9225 ft2

32. 0.01 m2

33. 153.9 ft2

34. 54.1 m2

35. 452.4 cm2

36. 452.4 in.2

37. 310 m2

38. 19 yd2

20. 1 ft2 or 192 in.2

21. 4320 in.2 or 3 yd2

22. 1 ft2 of 162 in.2

23. 8000 cm2 or 0.8 m2

24. 5.7 m2 or 57,000 cm2

25. 120,000 cm2 or 12 m2

26. 6000 ft2 or 666 yd2

27. 400 m2

28. 64 ft2

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1–7GEOMETRY LESSON 1–7

18.

16 units

19.

38 units

13

18

23

964

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Page 98: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1–7GEOMETRY LESSON 1–7

39. 24 cm2

40. 80 in.2

41. a. 144 in.2

b. 1 ft2

c. 144; a square whose sides are 12 in. long and a square whose sides are 1 ft long are the same size.

42. a. 30 squaresb. 16; 9; 4; 1c. They are =.

Post 1-10

48. Answers may vary. Sample: For Exercise 46, you use feet because the bulletin board is too big for inches. You do not use yards because your estimated lengths in feet were not divisible by 3.

49. 16 cm

50. 96 cm2

51. 288 cm

43. 3289 m2

44–47. Answers may vary. Check students’

work. Samples are given.

44. 38 in.; 90 in.2

45. 39 in.; 93.5 in.2

46. 12 ft; 8 ft2

47. 8 ft; 3.75 ft2

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Page 99: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1–7GEOMETRY LESSON 1–7

52. a. Yes; every square is a rectangle.

b. Answers may vary. Sample: No,

not all rectangles are squares.

c. A = ( ) or A =

53. 512 tiles

56. 38 units

57. 54 units2

58. 1,620,000 m2

59. 30 m

60. (4x – 2) units

61. Area; the wall is a surface.

62. Perimeter; weatherstripping must fit the edges of the door.

54.

perimeter = 10 unitsarea = 4 units2

55.

perimeter = 16 unitsarea = 15 units2

P4

P2

162

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Page 100: Geo chapter01power point

63. Perimeter; the fence must fit the perimeter of the garden.

64. Area; the floor is a surface.

65. 6.25 units2

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1–7GEOMETRY LESSON 1–7

b.

c. 25 ft by 50 ft

66. a. base heightarea

1 98  98

2 96 192

3 94 282

::

24 521248

25 501250

26 481248

::

47  6 282

48  4 192

49  2  98

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Page 101: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1–7GEOMETRY LESSON 1–7

67. a. 9b. 9c. 9d. 9

68. units2

69. units2

70. (9m2 – 24mn + 16n2)

units2

71. Answers may vary. Sample: one 8 in.-by-8 in. square + one 5 in.-by-5 in. square + two 4 in.-by-4 in. squares

72. 388.5 yd

73. 64

83. 9.2 units; (1, 6.5)

84. 6.7 units; (–2.5, –2)

85. 90

86. WI RI

87. 62 units

88. 18 units

89. 6 units

90. 33 units

74. 2336

75. 540

76. 216

77. 810

78. (15, 13)

79. 8.5 units; (5.5, 5)

80. 5.8 units; (1.5, 5.5)

81. 13.9 units; (3, 5.5)

82. 6.4 units; (–2, 3.5)

3a20

25a2

4

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Page 102: Geo chapter01power point

Perimeter, Circumference, and AreaPerimeter, Circumference, and AreaGEOMETRY LESSON 1-7GEOMETRY LESSON 1-7

256 in.2

81 cm2

296 in.

30 ft2

42 units

A rectangle is 9 ft long and 40 in. wide.

1. Find the perimeter in inches.

2. Find the area in square feet.

3. The diameter of a circle is 18 cm. Find the area in terms of .

4. Find the perimeter of a triangle whose vertices are X(–6, 2), Y(8, 2), and Z(3, 14).

5. Find the area of the figure below. All angles are right angles.

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Page 103: Geo chapter01power point

Tools of GeometryTools of GeometryGEOMETRY CHAPTER 1GEOMETRY CHAPTER 1

1. Div. each preceding

term by –2; , –

2. Add 2 to the preceding term; 10, 12

3. Rotate the U clockwise one-quarter turn. Alphabet is backwards;

8. B

9. a. 1b. infinitely manyc. 1d. 1

10. 29,054.0 ft2

11. never

12. sometimes

13. never

14. always

15. never

4. Answers may vary. Sample: 1, 2, 4, 8, 16, 32, . . .1, 2, 4, 7, 11, 16, . . .In the first seq. double each term. In the second seq., add consecutive counting numbers.

5. A, B, C

6. Answers may vary. Sample: A, B, C, D

7. Answers may vary. Sample: A, B, D, E

12

14

TEST

Page 104: Geo chapter01power point

16. 10

17. a. (11, 19)b. MC = MD = 136

18. 19.1 units

19. 800 cm2 or 0.08 m2

20. 12.25 in.2

21. 63.62 cm2

22. 7

23. 9

Tools of GeometryTools of Geometry

31. 33 yd2

1. D

2. G

3. B

4. H

5. B

6. I

7. B

8. H

9. 61 in.

10. 756 in.2

11. 207 in.

12. 2 in.

24. Answers may vary. Sample: Some ways of naming an can help identify a side or vertex.

25.

26. Bisector27. VW28. 7 units29. AY30. E, AY

13

12

14

GEOMETRY CHAPTER 1GEOMETRY CHAPTER 1

TEST