if look at the picture below
the height, and radius for both is the same, whatever those may be
thus [tex]\bf \begin{array}{llll}
\textit{volume of a cylinder}\\\\
V=\pi r^2 h\\\\
V=whatever
\end{array}\qquad
\begin{array}{llll}
\textit{volume of a cone}\\\\
V=\cfrac{\pi r^2 h}{3}\\\\
V=\cfrac{whatever}{3}
\end{array}[/tex]
