Basic Mathematics for College Students

828 Chapter 9 An Introduction to Geometry

The total area of the shaded figure is

The area of the shaded figure is 194 cm^2.

194 cm^2

Atotal130 cm^2 64 cm^2

AtotalAtrapezoidAsquare

To find the area of an irregular shape, we must

sometimes use subtraction.

To find the area of the shaded figure below, we subtract the area

of the triangle fromthe area of the rectangle.

AshadedArectangleAtriangle

REVIEW EXERCISES

65. Find the perimeter of a square with sides 18 inches
    long.


66. Find the perimeter (in inches) of a rectangle that is
    7 inches long and 3 feet wide.
    Find the perimeter of each polygon.


67. 
    

68.

69. The perimeter of an isosceles triangle is 107 feet. If
    one of the congruent sides is 24 feet long, how long
    is the base?


70. a. How many square feet are there in 1 square
    yard?
    b. How many square inches are in 1 square foot?

Find the area of each polygon.

71. 3.1 cm

3.1 cm

3.1 cm 3.1 cm

6 m

4 m

4 m

8 m

6 m

8 m

4 m

4 m

8 m

72.

73.

74.

75.

76.

77.

20 ft

8 ft

4 ft

12 ft

20 ft

8 ft

12 ft

14 ft

18 cm

8 cm

12 cm

10 in.

40 in.

30 ft

20 ft 15 ft

150 ft

50 ft