Rectangular coordinates and polar coordinates are two different ways of locating a point on a plan using two numbers.
                                       
In polar coordinate system
, each point on a plane is determined by a distance and an angle. It is represented as $(r,\theta )$ where "r" represents the length from the point to the origin and $\theta$ represents the angle that makes with the horizontal axis. In the polar system, the origin is called as pole and a ray from pole is called the polar axis.
                          Polar Coordinate System
In rectangular coordinate system, each point in a plane is determined by a pair of coordinates. It is represented as (x, y) where "x" represents horizontal distances from origin and "y" represents vertical distances from the origin.
                         Rectangular Coordinate System
If the plane of rectangular coordinate system and polar coordinate system are enclosed on each other, such that the pole coincides with the origin and the polar axis coincides with positive x-axis, any point can be referenced either the polar coordinates $(r, \theta)$ or rectangular coordinates (x, y).
                          
       Rectangular to Polar Conversion
To convert from rectangular to polar coordinate, we need to solve this triangle.
We use the following equations:
                       $r = \sqrt{x^{2}+y^{2}}$

                       $\theta = tan^{-1}($$\frac{y}{x}$)