Question #N396
The area of a circle is 36$\pi$ square meters. What is the circumference of the circle, in meters?
A. 6$\pi$
B. 12$\pi$
C. 18$\pi$
D. 36$\pi$
Correct Answer is: B
The area of a circle is given by $A = \pi r^2$, where $r$ is the radius of the circle. We are given that the area is 36$\pi$ square meters, so $36\pi = \pi r^2$. Dividing both sides by $\pi$ gives $36 = r^2$. Taking the square root of both sides gives $r = 6$. The circumference of a circle is given by $C = 2\pi r$. Substituting 6 for $r$ gives $C = 2\pi(6) = 12\pi$.