Look something like this. And so this region is this region. But it's going to be the base of a three-dimensional shape where any cross-section, if I were to take a cross-section right over here, is going to be a square. So whatever this length is, we also go that much high. And so the cross-section is a square right over there. The cross-section right over here is going to be a square, whatever the difference between these two functions is, that's also how high we are going to go. This length, which is six at this point, this is also going to be the height.