Question

What is the exact area of a circle with a diameter of 18 feet?

A.
36π square feet

B.
81π square feet

C.
324π square feet

D.
1296π square feet

@StudyGurl14

Answer 1

A=(pi)r^2
D=2r
18=2r
radius=??

Answer 2

I tink its A. 36π

Answer 3

why do you think it is A?

Answer 4

cuz 18*2=36

Answer 5

They give you a diameter of 18. you need to find the radius. The diamter is 2 times the radius, so you need to divide 18 by 2 to find teh radius. then plug it into the formula @acxbox22 gave

Answer 6

first what is the radius if we have a diameter of 18?

Answer 7

9?

Answer 8

yes
now plug 9 into A=pi(9^2)

Answer 9

WAIT! its 81! i kno! :P