if it has a diameter of 8, that means its radius is half that, or 4.
[tex] \bf \textit{volume of a cone}\\\\
V=\cfrac{\pi r^2 h}{3}~~
\begin{cases}
r=radius\\
h=height\\[-0.5em]
\hrulefill\\
r=4\\
h=5
\end{cases}\implies V=\cfrac{\pi (4)^2(5)}{3}\implies V=\cfrac{80\pi }{3}
\\\\[-0.35em]
\rule{34em}{0.25pt}\\\\
~\hfill \stackrel{using~\pi =3.14}{V= 83.7\overline{3}}~\hfill [/tex]
