# How do you find the equation of the circle, given the center and radius (0,0);4?

Jan 3, 2016

The equation of the circle would be ${x}^{2} + {y}^{2} = 16$

#### Explanation:

The general equation of a circle is:
${\left(x - a\right)}^{2} + {\left(y - b\right)}^{2} = {r}^{2}$
where $a$ is the $x$ coordinate of the center, $b$ is the $y$ coordinate of the center, and $r$ is the radius of the circle.

Applying this to your conditions, we get:
${\left(x - 0\right)}^{2} + {\left(y - 0\right)}^{2} = {4}^{2}$

which is

${x}^{2} + {y}^{2} = 16$