The volume of a cylinder is given by the following formula:
[tex]V=\frac{\pi\cdot h\cdot d^2}{4}[/tex]Where h is the height and d is the diameter.
We can consider the length of the pipe as the height of the cylinder.
Then h=25 ft and d=6 ft. Replace these values in the formula and solve for V:
[tex]\begin{gathered} V=\frac{3.14\cdot25ft\cdot(6ft)^2}{4} \\ V=\frac{3.14\cdot25ft\cdot36ft^2}{4} \\ V=\frac{2826ft^3}{4} \\ V=706.5ft^3 \\ V\approx707ft^3 \end{gathered}[/tex]The volume is 707 ft^3