Circle is a defined as the locus of points in space with equal distance from the center. The distance between center and any of the points on the surface is known as the radius. The distance between two points on the surface through the center is the diameter. In geometry, the equation of a circle can be represented in two ways. They are, 
In general form:

Where A, B, C are constants

In standard form:

Where (a,b) is the center
           r is the radius of the circle

Steps for finding the center point and the radius of a circle is given below:

Step1: Find out the values of a,b and r.
Step2: (a,b) is the center of the circle and r is the radius of the circle.
Step3: Draw the circle using the given points.