[tex]\textit{volume of a cone}=\cfrac{\pi r^2h}{3}\qquad
\begin{cases}
r=radius=\frac{diameter}{2}\\
h=height
\end{cases}[/tex]
you're given the height of the cone,
and the diameter, notice, the radius is half-diameter,
so, split that diameter in half, to get the radius,
plug in your values
