Other Helpful Sites
http://www.spsu.edu/math/edwards/1113/unitcircle.htm
http://www.mathmistakes.info/facts/TrigFacts/learn/uc/uc.html
http://www.sparknotes.com/math/trigonometry/trigonometricfunctions/section5.rhtml
http://www.youtube.com/watch?v=ZffZvSH285c

Works Cited

Everything on this website came from the minds of the creators, no outside sources were used.