If you are using the word diameter, I am going to assume that the pool is round. A round pool represents the shape of a cylinder. The volume for a cylinder is [tex] \pi r^2h[/tex]. Diameter is twice the radius, so our radius is half of 27 which is 13.5 feet. So our formula is [tex]V= \pi (13.5)^2(4)[/tex]. That's the forumula for it. That actual volume measure is [tex]729 \pi ft^3[/tex], or multiplying in pi as 3.14, it's 2289.06 cubic feet.
