# What will be the equation of the circle with a center at (–4, 9) and a diameter of 10 units?

We can make use of the standard form of the equation of the circle.

## Answer: The equation of the circle, can be given as ^{ }(x + 4)^{2} + (y - 9)^{2} = 25.

Go through the step-by-step procedure to get the final equation of the circle.

**Explanation:**

Given, center coordinates = (-4, 9) and diameter = 10 units.

radius = diameter / 2 = 5 units

Using the standard equation of the circle, which is :

(x - h)^{2} + (y - k)^{2} = r^{2} , where:

h = x coordinate of the center

k = y coordinate of the center

r = radius of the circle.

Thus on substituting the value of h, k, and r in the standard equation, we get:

(x + 4)^{2} + (y - 9)^{2} = 5^{2}

⇒^{ }(x + 4)^{2} + (y - 9)^{2} = 25