Q:

What is a circle's area if its radius is $\pi$?

The area of a circle equals $\pi r^2$. If a circle's radius is $\pi$, what is its area? I believe the answer is $\pi^3$, right?

A:

Correct.  Given $\ A_\circ(r) = \pi r^2 $, now let $\ r = \pi$. Now $\ A_\circ(\pi) = \pi (\pi)^2 = \pi^3 $.

