Pyramid SA
For a Pyramid with base coordinates (1,1,0), (1,-1,0), (-1,1,0), and (-1,-1,0).
In general the Surface Area of the four triangles is a function of three variables.
The level sets of which are *quite* difficult to solve for or visualize. The one trick I have found is if you pick a level set, say
and restrict to the plane , we get the cylinder , which, when restricted to that plane is an ellipse.