The radius is going to be h over 2. And so the area of the water surface is going to be pi r squared, pi times the radius squared, h over 2 squared. That's the area of the surface of the water. And of course, we still have the 1 third out here, and we're still multiplying by this h over here. So let me see if I can simplify this. So this gives us 1 third times pi h squared over 4 times another h, which is equal to, we have pi h to the third power over 12. So that is our volume.