To figure out the size of a rectangle that would represent the swimming pool, you will use the formula for volume of a rectangle or prism to solve for the area of the base.
V = Bh 1200 = 5B B = 240 square feet
To get an area of 240 ft.², you could use the dimensions 10' x 24'. Another possibility would be 8' x 30'.
Get the Radius which is 8 then multiply (8)(8) and then get 64, finally you need to do 64*3.14 to get the final answer of 200.96. Then you need to divide that by two which would give you the final answer of 100.48