Answer
$V=\dfrac{\pi hr^{2}}{3}$
Work Step by Step
$r=\sqrt{\dfrac{3V}{\pi h}}$ $;$ Solve for $V$:
$r=\sqrt{\dfrac{3V}{\pi h}}$
Square both sides:
$r^{2}=\Big(\sqrt{\dfrac{3V}{\pi h}}\Big)^{2}$
$r^{2}=\dfrac{3V}{\pi h}$
Take $\pi h$ to multiply the left side:
$\pi hr^{2}=3V$
Take the $3$ to divide the left side:
$\dfrac{\pi hr^{2}}{3}=V$
Rearrange:
$V=\dfrac{\pi hr^{2}}{3}$
