Step-by-step explanation:
[tex]v = \frac{\pi r {}^{2}h }{3} [/tex]
[tex]3v = \pi {r}^{2} h[/tex]
[tex] \frac{3v}{\pi h} = {r}^{2} [/tex]
[tex] \sqrt{ \frac{3v}{\pi h} } = r[/tex]
