Functions (mathematics)/Graphs/Polar Coordinate

Polar Coordinate
In mathematics, the polar coordinate system is a two-dimensional coordinate system in which each point on a plane is determined by a distance from a reference point and an angle from a reference direction.

A point on Cartesian coordination will be A (r,θ). Where r represents length in r direction and θ represents angle of incline
 * Examples_of_Polar_Coordinates.svg