we know that
the volume of a cone is equal to
[tex]V=\frac{1}{3}\pi r^{2}h[/tex]
where
r is the radius of the base of the cone
h is the height of the cone
in this problem we have
[tex]D=12 ft\\ r=(D/2)=12/2=6ft\\ h=15 ft[/tex]
Substitute in the formula above
[tex]V=\frac{1}{3}*\pi*6^{2}*15[/tex]
[tex]V=180*\pi\ ft^{3}[/tex]
[tex]V=565.49\ ft^{3}[/tex]
therefore
the answer is
the volume of the cone is [tex]180*\pi\ ft^{3}[/tex] or [tex]565.49\ ft^{3}[/tex]
