Well, we have also been given the formula for the volume of a cone right over here. The volume of a cone is 1 third times the area of the base of the cone times the height. And we won't prove it here, although we could prove it later on, especially when we start doing solids of revolutions in integral calculus. But we'll just take it on faith right now that this is how we can figure out the volume of a cone. So given this, can we figure out an expression that relates volume to the height of the cone? Well, we could say that volume, and I'll do it in this blue color, the volume of water is what we really care about. The volume of water is going to be equal to 1 third times the area of the surface of the water, area of water surface times our height of the water, so times h. So how can we figure out the area of the water surface, preferably in terms of h?