Bell Work:

Simplify (-2)4

Answer:

16

Lesson 37:Areas of combined

polygons

The areas of some polygons can be found by dividing the polygon into smaller parts and finding the area of each part.

Formulas to be familiar with:

Area of rectangle: length x width

Area of triangle: ½ base x height

Pythagorean Theorem: a + b = c2 2 2

Example:

Find the area of this figure.

4 cm

8cm

6 cm

Answer:

Area of rectangle = 24 cm

Area of triangle = 4 cm

Area of polygon = 28 cm

2

2

2

Example:

Use a calculator to estimate the area of this lot.

100 ft110 ft

60 ft

Answer:

x + 100 = 110

≈ 46

Area of triangle ≈ 2300 ft

Area of rectangle = 6000 ft

Area of lot = 8300 ft

2 2 2

2

2

2

Example:

In the figure, AD is 40 cm and DC is 30 cm. Point B is the midpoint of AC and Point E is the midpoint of AD. Find the perimeter and the area of the quadrilateral BCDE.

____

____

A

B

C

DE

Answer:

Area of figure BCDE = 450 cm

2

HW: Lesson 37 #1-30