Posted by becky on .
how do you figure out the diameter of a pipe that is 40 feet high and holds 200000 gallons

math 
Steve,
v = pi r^2 h
200000 gallons = 26736.11 ft^3
26736.11 = pi r^2 (40)
r^2 = 212.76
r = 14.59 ft
diameter is thus 29.18 ft