1000 feet^3
5 x 3 = 15 x 6 = 90 cubic feet
6,084*pi cubic feet or about 21,364.56 cubic feet.
This cylinder has a volume of 100.528 cubic feet.
0.135 cubic feet
4x4x3 = 48 cubic feet
a cubic room
6 x 6 x 12 = 432 cubic feet.
Almost 6 feet tall
624 cubic feet
A cubic foot is a measure of volume, not of length or height.
It would help to know what units of measurement are used for 20*20*8. Are they feet or yards or metres or something else?But in the US, most rooms are measured in feet, and 8 feet tall is about right for a room in a house, so (20 ft)*(20 ft)*(8 ft) = 3200 cubic feet.