We chose a point in a plane that is called the pole and is labeled O.
Then we draw a ray starting from O called the polar axis (Usually corresponds to the positive x-axis)
if point P is any other point in the plane, let r be the distance from O to P and let θ be the angle between the polar axis and the line OP
This point is represented by the order pair (r,θ) and r,θ are called polar coordinates of P.
We extend the meaning of polar coordinates to the case which r is negitive by agreeing that the points (−r,θ) and (r,θ) lie on the same line through O the same radius from O but opposite
