Math 90Math 90

9.1

Warm-up/QuizWarm-up/Quiz

Without using any notes see how many Without using any notes see how many formulas you can remember:formulas you can remember:

Area of a triangleArea of a triangle

Area of a kiteArea of a kite

Area of a circleArea of a circle

Area of a parallelogramArea of a parallelogram

Area of a trapezoidArea of a trapezoid

PerimeterPerimeterPerimeterPerimeterPerimeter is the measure of the distance around a polygon.

Definition: a closed figure that consists of line segments (eg. triangles and quadrilaterals are polygons).

Perimeter is calculated using a Four Step Method:

1. Diagram

2. Formula

3. Substitution

4. Solution

ExamplesExamplesExamplesExamplesCalculate the perimeter of the following RECTANGLE:

6m

4m1. Diagram1. Diagram

2. Formula2. Formula

3. Substitution3. Substitution

4. Solution4. Solution

2 2P l w

2(6) 2(4)

12 8

20m

The perimeter is 20m.

The perimeter is 20m.

Don’t forget your

units!

Examples ContinuedExamples ContinuedExamples ContinuedExamples ContinuedWhat is the perimeter of this RHOMBUS?

3cm1. Diagram1. Diagram

2. Formula2. Formula

3. Substitution3. Substitution

4. Solution4. Solution

4P b

4(3)

12cm

The perimeter is 12cm.

The perimeter is 12cm.

AreaAreaAreaAreaArea is the measure of the number of square units contained within any polygon.

Area is also calculated using a Four Step Method:

1. Diagram2. Formula3. Substitution4. Solution

Hmmm… I wonder what the area is of the wall I’m painting?

ExamplesExamplesExamplesExamplesWhat is the area of the following RECTANGLE?

1. Diagram1. Diagram

2. Formula2. Formula

3. Substitution3. Substitution

4. Solution4. Solution

3m

12mA lw

2

(3)(12)

36m

The area is 36m2.The area is 36m2.

Try these:Try these:Try these:Try these:

1. Diagram1. Diagram

2. Formula2. Formula

3. Substitution3. Substitution

4. Solution4. Solution

5m7m

2

bhA 2A r

6m

(6)(7)

2

2

42

2

21m

The area is 21m2.

The area is 21m2.

The area is .The area is .

QuizQuizNumber your paper Number your paper from 1 -6.from 1 -6.

Place this list at the top Place this list at the top of your paper.of your paper.

State the name of the State the name of the polygon and which polygon and which formula you would use formula you would use to find area.to find area.

1)1) 2) 2)

3)3) 4) 4)

5)5) 6) 6)