It's going to be a function of y. We could call it g of y. It's going to be the square root of y. So area is equal to pi r squared, which means that the area of this thing is going to be pi times our radius squared. Our radius is square root of y. So this thing is going to be equal to pi squared of y squared is just pi times y. Now, if we want the volume, we just have to multiply the area of the surface times the depth, times dy.