I just posted this month's Math Forum project: The Pentaflake. This is a 2D fractal created from just one simple pentagon. The only SketchUp tools needed to complete the pentaflake are Rotate and Erase - simple and elegant.
When you fill in the missing spaces with faces, you can get some beautiful patterns:
As usual, there is a Student Version which includes a few questions, and a Teacher Version that provides the answers.
It's free - check it out!
PS - I ran across the pentaflake while creating the hexaflake shown below, which is the topic of one of this month's Projects of the Month.
Anyone can design anything in 3D! http://www.3dvinci.net/