Geometry Cross Sections with Play Dough

The other night I was tutoring one of my high school geometry students.  We were working on cross sections and identifying what shapes were made when you "cut" into the shape with a plane at different angles.  The images on his homework were making it difficult to easily see what shapes were being made.

I grabbed my youngest son's play dough and we began making 3-D shapes.  We made spheres, cubes, triangular prisms, and even managed to make a hexagonal prism!

Materials Needed:

Play dough
Kitchen knife

Here's a look at the sphere we did:

We created a circle when it was cut.