Polar coordinates

Polar coordinates are similar to coordinates on a unit circle but a little different.  To graph polar coordinates you need to use r and theta.  Theta is the angle of the coordinate and r is equal to the radius.  There are four different ways to graph polar coordinates with a positive r and theta, negative r and theta, positive r negative theta, negative r positive theta.  You can also convert rectangular points to polar points using  the formula r^2=x^2+y^2; tantheta=y/x.  To convert polar coordinates to rectangular use the formula x=rcostheta y=rsintheta.  Here is a picture of a polar coordinate graph.