Answer:
4187 ft³
Explanation:
πr³
π = 3.14
r = radius
the diameter is the straight line that passes through the centre of a circle and touches the two edges of the circle.
A radius is half of the diameter
diameter = 2r
Radius = 20 / 2 = 10 feet
(4/3) x 3.14 x 10³ = 4187 ft³