how to find equation of a circle when the diameters of the circle are given?

Question

To know how to find the equation of a circle when the diameters of the circle are given 

Answer 1

An equation of the circle with center (h, k) and radius r is                                   (x-h)² + (y-k)² = r^2.

 

If you know the endpoints of a diameter, then (h, k) is the midpoint of the diameter and r is the distance from (h, k) to either of the diameter's endpoints.  

Answer 2

The equation of a circle is

 

x² + y² = r²

 

where:

r = radius

and the center of the circle is located at the origin.

 

 

Two coordinates will be given as the endpoints of the diameter.  You will find the distance between those coordinates to find the diameter.

 

The midpoint of the two coordinates is the center of the circle. 

 

To find the radius, divide the diameter by 2.