Answer:
Formula for volume of cylinder;
V = π
h
Where 'π' represents pi(22/7 or 3.14), 'r' represents the radius which is 1/2 x diameter (half of diameter = radius) which is squared, and 'h' which represents the height.
To find the radius of the diameter 5, we must find 1/2 of 5:
1/2 x 5
5/2 = 2.5 is our radius.
Now we plug these into our equation:-
V = π
h
V = 3.14(2.5^2) x 20
V = 3.14(6.25) x 20
V = 19.625 x 20
V = 392.5 cubic feet.