PBS
Pbs Learning Media: Cyberchase: Fixing the Teleporter Part 1
In this Cyberchase video, the Teleporter breaks and the CyberSquad must try to fix it using clues given to them by Ms. Fileshare. This is one in a series of two problem-solving videos. [3:49]
Cut the Knot
Cut the Knot!: Interactive Mathematics: Geometry Articles, Theorems, Problems
Contains over five hundred Geometry articles, problems, puzzles, and games. Some sites relating to circles are provided within this list.