If the area of a disc inscribed in a square is 36pi^2, what is the area of the square?
If the disc is inscribed in the square, then we know that one side of the square is twice the radius of the circle. The area of the square is $\displaystyle 36 \pi ^2$ (typo?) so the radius must be $\displaystyle 6 \sqrt{ \pi }$, thus the side of the square is $\displaystyle 12 \sqrt{ \pi }$ and thus the area of the square is $\displaystyle \left ( 12 \sqrt{ \pi } \right ) ^2 = 144 \pi$.
-Dan