Question

Which circles have an area of 36pift2?

Choose all answers that are correct.
A. a circle with a radius of 6 ft
B. a circle with a diameter of 6 ft
C. a circle with a radius of 12 ft
D. a circle with a diameter of 12 ft

Answer 1

area=pi times radius^2
area=36pi
36pi=pi times radius^2
divide both sides by pi
36=radius^2
square root both sides
6=radius

2radius=diameter
2 times 6=12
radius=6
diamater=12

the answers area A and D
(if you know your radius and diameter, you would know that diameter is 2 times radius and you could eliminate 2 choices imedietly (B and C))