Shodor Education Foundation
Shodor Interactivate: Lessons: Polar Coordinates
Introduces students to graphing in the polar coordinate plane.
CK-12 Foundation
Ck 12: Polar Form of a Complex Number
[Free Registration/Login may be required to access all resource tools.] Here you will learn how to convert complex numbers from rectangular form to polar form. You will also explore the graphs of complex numbers on a polar graph.
Other
Dans Math: Lessons: Trigonometry
College professor Dan Bach reviews basic trig concepts, including trig functions, right triangles, circles, radians, and polar coordinates. Site includes animated graphs and detailed examples.