# How do you write an equation for a circle with center (5, -4) and radius 11?

Dec 23, 2015

${\left(x - 5\right)}^{2} + {\left(y + 4\right)}^{2} = 121$

#### Explanation:

Any circle centred at $\left(a , b\right)$ and with radius $r$ has equation
${\left(x - a\right)}^{2} + {\left(y - b\right)}^{2} = {r}^{2}$.

So in this particular case the equation will be

${\left(x - 5\right)}^{2} + {\left(y + 4\right)}^{2} = 121$