Answer:
[tex]760.5\pi \: {ft}^{2}[/tex]
Step-by-step explanation:
Volume of a cylinder =
[tex]\pi \: {r}^{2} h[/tex]
[tex] = \pi \times {6.5}^{2} \times 18[/tex]
[tex] = 760.5\pi \: {ft}^{2} [/tex]
Volume of the pile =
[tex]760.5\pi \: \: {ft}^{2} [/tex]