Vocabulary

• Square

• Parallelogram

• Pair

• Parallel

• Pair of equal sides

• Rectangle

• Rhombus

• Quadrilateral

• Trapezoid

Parallel Lines

• Parallel lines exist everywhere, if you look for them. Here are some examples of parallel lines.

Parallel Lines

These are lines that never intersect.Intersect means that the lines never touch, they always stay the same distance from each other.

For Example:These two pencils are parallel

What are not parallel lines?

• Any lines that intersect are not parallel.

Share with your partner

Look around the room and see if you can find any parallel lines. What do you see?_____________ has parallel lines.

Explain to your partner what a parallel line is and where you can find them.

Parallel lines are _______________ and you can find them ______________.

Pairs of Parallel Lines

• When we are talking about parallel lines, we are always talking about pairs of parallel lines.

• What is a “pair”? • How many are in a pair?

Let’s look at this…

What things come in pairs?

Things that

come in pairs

Pair …

of eyesof shoesof handsof socksof crutches

“Pairs”

• All of these things are pairs, but how many are in the pair?

• Tell your partner how many socks are in a pair.

That’s

right, 2!!!

Pairs

2 socks = 1 pair of socks2 shoes = 1 pair of shoes

1 pair of crutches = 2 crutches1 pair of eyes = 2 eyes

2 hands = 1 pair of hands

Let’s see if y

ou

get this…Good

Job!!

Polygons with Parallel Lines

• Some polygons have parallel lines. • Remember, you have to have 2 lines (pair) to

make 1 pair of parallel lines.

• Let’s take a look

Parallel lines exist in geometryIf you look at polygons you can find parallel

lines. Remember that parallel lines never touch.

Can you guess which polygon has parallel lines? Talk to your partner and explain which polygon has

parallel lines:The polygon on the right/left has parallel lines

because ________________.

Count the pairs of parallel lines in the polygons

This shape has _______ pairs of parallel lines.

This shape has _______ pairs of parallel lines.

This shape has _____ pairs of parallel lines.

21 pair 2 pairs

1 pair

1 pair

2 pairs

2

1

Find how many pairs of parallel lines are in the polygons.

Pairs _____

Pairs _____

Pairs _____

Pairs _____

Pairs _____

Pairs _____

We learned that the prefix quadri means 4, and that a polygon with four sides is called a quadrilateral.Let’s take a look at some different types of quadrilaterals.

quadrilaterals

• How do you know if a polygon is a quadrilateral?

• If a polygon has 4 sides, it is• quadrilateral.• The sides and angles are • what determine the type • of quadrilateral it is.

1

3

24

square

• The perfect quadrilateral. What makes a square?

• A square has 4 equal sides. • A square has 4 right angles.

rectangle

• What makes a rectangle?

• A rectangle has 2 pairs of equal sides. • A rectangle has 4 right angles. • That means that a square is also a rectangle.• Turn to your partner and tell them why a square

is a rectangle.• A square is a rectangle because

________________.

rhombus

• The rhombus is the cousin of the square.

• A rhombus has 4 equal sides. • But, a rhombus can have any angles. • That means that a square is also a rhombus.

Turn to your partner andTell them why a square isA rhombus.

A square is a rhombus because ________________________.

parallelogram

The parallelogram is the cousin of the rectangle.• A parallelogram has 2 pairs of equal sides. • But, a parallelogram can have any angles. • Talk to your partner. Do you think that a

square or a rectangle is a parallelogram. Why?

my turn

Which figure has two pairs of equal sides?

A circleB hexagonC rectangleD octagon

your turn

Which figure always has 4 equal sides?

A circleB hexagonC rectangleD square

my turn

One side of a rectangle is 3 ins. long. Another side is 7 ins. long. What are the lengths of the other sides of the rectangle?

A They could be any lengthB 3 ins. and 3ins.C 7 ins. and 7 ins.D 3 ins. and 7 ins.

7 in

7 in

3 in 3 in

your turn

One side of a square is 5 cms. long. What are the lengths of the other sides of the square?

A 5 cmsB 10 cmsC 15 cmsD 20 cms

5 cms

5 cms

5 cms5 cms

So what did you learn today?

• What is a pair?• A pair is ________________________.• What are parallel lines?• Parallel lines are __________________.• What is a quadrilateral?• A quadrilateral is __________________.• What are the 4 different types of quadrilaterals?• ___________, ___________, __________, and

___________ are different types of quadrilaterals.