# Question #86d19

##### 2 Answers

#### Explanation:

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

#### Explanation:

We know that, the eqn. of a circle having centre at point

and radius

Since the **Mid-point** of a **Diameter** is the **Centre** of the

circle, we see that, the centre

Also,

Therefore, the eqn. of the circle is,

**N.B. :-**

We can use the following formula to find the eqn. of a circle having

**diametrically opposite points**

**Enjoy Maths.!**