I need to label the intersection between a plane and a surface. A perfect, no need to explain more example is this picture taken from wikipedia:

I need to be able to show the red lines that you see there.

http://upload.wikimedia.org/wikipedia/commons/e/eb/Minimal_surface_curvature_planes-en.svg

Can someone help?

Is there a way to solve an equation to show all integer solutions, assuming the problem has finite solutions. Examples would include elliptic curves.

I am just moving from Mathematica to Maple, since I just found out Maple is better suited to my needs. I checked some basic functions, and Maple seems to be pretty perfect. However, I cannot find a way to do a revolution plot. In Mathematica I usually used the command RevolutionPlot3D. But here, in Maple, I cannot find a way to do it. Can someone help?

Here is a sample of what I am talking about: