Polar Cooridinates Applet

We are used to decribing the location of a point on a graph with ordered pairs and x and y coordinates. This app will help you discover another way to describe the location of a point on a graph.
Could we describe location of point by its distance from the origin? Is this a unique description of the location? Could we describe the location by the distance and another factor? What would that be? How would we convert from (x, y) to the distance and this new factor?