A swimming pool can be compared to an enormous rectangle, if we choose to think of it that way, and in this example, it has 16,500 cubic feet as the volume of this large rectangle. Now the formula for calculating the area of such a rectangle is Depth*Length*Width=Volume. If we plug in the parts we already have, we get 10*75*Width=16,500. If we divide by 10 and 75 on both sides, we get Width=22.