So this cross section, if we're looking at it at an angle, and if the figure were transparent, it would be this cross section right over here. It would be that cross section right over here, which is a semicircle. If we were to take this cross section right over here along the y-axis, that would be this cross section, this larger semicircle. So given that, given what I've just told you, I encourage you to pause the video and see if you can figure out the volume of this thing that I've, I could shade it in a little bit. The volume of this thing that I've just started, this three-dimensional figure that we are attempting to visualize. So I'm assuming you've had a go at it. And one way to think about it is, well, let's just think about each of these.