Interactive Polar to Cartesian
This interactive demonstrates how the polar coordinate system and the cartesian coordinate system describe the same point in space. Polar describes a points as a radius and angle: P = (radius, angle). Cartesian describes points as a X and Y component: P = (x, y). Click and drag either point to change the current point for both systems. Toggle degrees to change between radians and degrees. Toggle gridlines to show the layout of each space.
To convert between the two systems, see how to convert from polar to cartesian.