Think about it. The area (the two dimensional version of volume) of a two dimensional shape, like a square, can be 2 feet by two feet. Multiply these together, and you get 4 feet^2, or four feet squared, This is because in order to get the volume, you multiply the base times the height, one side by the other. You make the feet "feet squared" because you are also multiplying the measurements together, too. In three dimensional shapes though, you have three different ways to go. You have the base, the height and the width beyond it. So you multiply them together and get 8 feet^3 or 8 feet cubed (you multiply three measurements together).
