Introduction to ways of labeling points on a plane by (x, y), their cartesian coordinates. Optional--extending this to (x,y,z) coordinates in 3-dimensional space, to (r,?) plane polar coordinates and to 3-dimensional polar coordinates (r,?, ... This lesson plan supplements: "Coordinates," section #5b: on disk Scelcoor.htm , on the web . ... Polar coordinates (r, ?) on the plane (2-dimensions) . ... Can systems of coordinates, other than the cartesian one, be used to label points on a plane? ...