Monday, June 25, 2012

Polar Coordinate System

The (x, y) co-ordinates of a point in the plane are called its Cartesian co-ordinates.But there is another way to specify the position of a point,and that is to use polar co-ordinates(r, θ). 

A polar coordinate system consists of a fixed point (called the pole or origin)and a ray from the origin (called the polar axis). The polar axis is usually horizontal and directed toward the right.

Every point in the polar coordinate system is described by an ordered pair of real numbers, (r, θ). The first coordinate describes the point's distance from the pole and the second coordinate describes the angle formed with the polar axis. 

Following conventions are used while using polar co-ordinates : 
  • θ is measured in radians. 
  • θ is measured from the polar axis ,and is measured as positive in an anticlockwise direction from the it, or negative in a clockwise direction from the polar axis.
This is a Java Applet created using GeoGebra from - it looks like you don't have Java installed, please go to


  1. Sanjay

    I have written a new theory (2003) on radical coordinates.
    Here we can situate a point (e.g. a planet) around a center in the surrounding sphere.
    The situation is made by means of a radius R with two (sub-index and super-index) angles of situation.
    These angles could be in motion by means of an angular speed, with which we can produce al type of figures and drawings.
    If you are interested, you can see in:

  2. Sure , thank you for visiting and your comment.