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 pi = 3.14

A) 471 sq. ft

B) 8831.25 sq. ft

C) 17662.5 sq.ft

D) 35325 sq ft

Answer 1

Answer: 8831.25 is correct

Explanation:

The area is 8831.25 sq. feet. The radius is 75 feet. The area of the semicircle is πr2/2. So you would have A = π·752 which is 17662.5 and then divide by 2 to get 8831.25.

Answer 2

so, πr^2 is the equation for the area of a circle, if we calculate that, it will equal 17662.5
we then half that to get the area (square feet) of the dead grass, which equals 8831.25 square feet, therefore choice B is the answer