While this site is no longer actively maintained, there are numerous resources here that teachers and students around the world have found valuable -- so I'm commited to keeping them available for all to use. Enjoy!
PDFs of individual Geometry lessons, largely aligned with Michael Serra's Discovering Geometry textbook.
GeoGebra's free dynamic Geometry canvas is an amazing way to visualize and experiment with Euclidean Geometry concepts.
A collection of videos that demonstrate basic compass constructions.
Use a virtual compass to create compass constructions. (Requires browser Java support.)
Interactive two-column proofs tool with a focus on triangle congruency theorems/conjectures.
Interactive two-column proofs tool, organized by topic and complexity.
A collection of AP Computer Science lessons aligned with Litvin & Litvin's Java Methods.