Answer:
From the formular given to Jane:
[tex]V = 13( {\pi r}^{2} )h[/tex]
making h the subject:
[tex]{ \boxed{ \boxed{h = \frac{V}{13\pi {r}^{2} } }}}[/tex]
making r the subject: »
[tex] {r}^{2} = \frac{V}{13\pi h} \\ \\ { \boxed{ \boxed{r = \sqrt{ \frac{V}{13\pi h} } }}}[/tex]