A cube is a three-dimensional object that is bounded by six square faces, with three meeting at each vertex. Because the faces of the cube are squares, each side of each face measures the same as the other ones. Therefore, in order to get the volume of a cube (the amount of space the cube occupies) we need to multiply:
height*length*width
In this example, the height of the cube is 12 inches. Therefore:
12*12*12 or 12^3 = 1728 cubic inches or 1 cubic feet