Right isosceles triangle cross sections with circular base

The base of this solid is a circle of radius 1 centered at the origin. The cross sections perpendicular to the [math]y[/math]-axis are isosceles right triangles. Drag the green point to see different cross sections.
[i]Developed for use with Thomas' Calculus, published by Pearson.[/i]

Information: Right isosceles triangle cross sections with circular base