What does 40 cubic feet look like?
The most compact form for 40 cubic feet is a sphere of radius
2.2 feet. A more easily visualised example may be a cube with sides
of 3.42 feet.
However, it could be a cuboid of dimensions 2x2x10 or 1x2x20 or
any one of an infinite number of options.
And, of course, it could be in the form of other 3-dimensional
shapes.