University of Saskatchewan (Canada)
University of Saskatchewan: Trigonometric Functions
This site examines the six trigonometric functions from a right triangle point of view. Provides information, examples, and lots of exercises for understanding.
Purple Math
Purplemath: Greek Letters and Their Names
When you are working with geometry and trigonometry, you will see a lot of Greek letters. It will be helpful to know how the names of these letters are spelled and pronounced.