A discussion of Christian Huygens' contribution to wave optics, and particularly to our understanding of the reflection and refraction of light. Excellent diagrams and a geometric proof on why the law of reflection is mathematically...

Discovering the properties of constructions, seeing proofs in action, and viewing problems come to life here with this wonderful use of technology in the classroom. Single steps are explained and illustrated one at a time so that the...

Dr. Math gives a student a hint on how to prove that an inscribed angle is equal to 1/2 the central angle. You should know what the central angle and inscribed angle are to utilize this site.