[tex]\bf \textit{volume of a cone}\\\\
V=\cfrac{\pi r^2 h}{3}\quad
\begin{cases}
r=radius\\
h=height\\
-----\\
V=75\pi \\
h=9
\end{cases}\implies 75\pi =\cfrac{\pi r^2\cdot 9}{3}\implies 75\pi =3\pi r^2
\\\\\\
\cfrac{75\pi }{3\pi }=r^2\implies 25=r^2\implies \sqrt{25}=r\implies 5=r[/tex]
