GeoGebra is a free, multi-platform software package combining dynamic geometry, algebra and calculus. You can use it in a lab environment, or for teacher-led classroom demonstrations.  It can be used as a standalone system, or you can easily generate interactive web pages for student exploration outside of class. 

This web site deals with using GeoGebra to create interactive explorations of plane symmetry. Try out some of GeoGebra's interactive features in the mini-applet at the right, or by clicking on the following links:

• Rotations and reflections in a finite design

• Translations and glide reflections in a plane tiling
  
  
• Symmerty in a strip pattern

Are you sold?  Can't wait to start creating your own applets?  Click here for links to additional resources, and for copies of the files we used in our presentation.

Image courtesy of SnowCrystals.com