Chapter 6 Circular Measure
Chap6 Circular Measure.doc
Angles and Radian Measure
http://www.gomath.com/algebra/angleradian.asp
http://www.geocities.com/CapeCanaveral/Launchpad/2426/page71.html
http://aleph0.clarku.edu/~djoyce/java/trig/angle.html
