Question

In the neighborhood park there is a circular grassy picnic area, but half of the grass has died. The city wants to replant the grass, but needs to know the square footage of the damaged area. If the circular picnic area is 150 feet across, what is the square footage of the damaged area? Let π = 3.14.
A) 471 sq. feet
B) 8831.25 sq. feet
C) 17662.5 sq. feet
D) 35325 sq. feet

Answer 1

The formula for the area of a circle is :

Area = PI x r^2

r is half the diameter which is given as 150 ft.

r = 150/2 = 75 feet.

The area of the circle is :

3.14 x 75^2 = 17662.5 sq. ft.

About half the area is damaged, divide the area above by 2:

Damaged area = 17662.5 / 2 = 8831.25 sq. ft.

The answer is B.