In order to determine the equation of a circle, we need to know its radius and the coordinates of its centre.
We are given the endpoints of a circle's diameter.
So let's find the coordinates of the centre using the midpoint formula;
Then, let's find the length of the diameter using the formula
Now, the equation of a circle is of the form
We know that, the eqn. of a circle having centre at point
Since the Mid-point of a Diameter is the Centre of the
circle, we see that, the centre
Therefore, the eqn. of the circle is,
We can use the following formula to find the eqn. of a circle having
diametrically opposite points