All right, now let's do this together. And first let's just try to visualize the solid. And I'll try to do it by drawing this with a little bit of perspective. So if that's our Y axis, and then this is our X axis right over here. And I can redraw region R. It looks something like this. And now let's just imagine a cross section of our solid. So it says the cross section of the solid taken perpendicular to the Y axis.