The base of a solid
is an elliptical region
.
Cross sections perpendicular to the
-axis are isosceles right triangles with hypotenuse on base.
Draw the top view of the solid with parallel cross sections of length as
and radius of the base
is on -axis..

Observe the figure,
\From the pythagotrean theorem,
.
Consider the side of the isosceles triangle as
.

.
Area of the cross section is
.


.
Consider
.

.
Substitute
in
.
.
Find the volume of the solid by integrating the area with respect to
over the limits
to
.




Volume of the solid is
.
Volume of the solid is
.