Question

A circle has an area of 36π square centimeters. What is the diameter?

Answer 1

Area of circle=pi*radius^2
radius=1/2*diameter.
36pi=pi*radius^2
36=radius^2
radius=6
radius=1/2*diameter
6=1/2*diameter
diameter=12 cm.

Answer 2

area of circle = pi * r^2 = pi * (d/2)^2 since diameter/2 = raidus

so 36 * pi sqin = pi * (d/2)^2 divide both sides by pi.....
36 *pi / pi = (d/2)^2 take the square root of both sides.....
sqroot(36) = d/2 multiple both sides by 2
2* sqroot(36) =d
d = 2*6 = 12

so the guy above is also right