... did you correctly answer the question on the previous page? You may be wondering how to calculate the bearing (q) and distance (L) from the DY and DX values.

The relationship can be solved by trigonometry.

L = Ö( DY² + DX² ) .... remember pythagorus theorem?

and the bearing q can be calculated by

Tanq = DY/DX

!As the signs of the function will differ depending on the sign of DY and DX , the correct bearing MUST be determined from the resulting angle value.

See the sketch and the table to the right.

• Given a rectangular coordinate you can calculate a polar coordinate.
• Given a polar coordinate you can calculate a rectangular coordinate.

On the next page you can demonstrate your learning on polar/rectangular coordinates in an interactive applet!