# A circle is centered at (2, -5) and has radius 3. How do you write its equation in standard form?

Jan 20, 2016

${\left(x - 2\right)}^{2} + {\left(y + 5\right)}^{2} = 9$

#### Explanation:

The standard form of the equation of a circle is :

${\left(x - a\right)}^{2} + {\left(y - b\right)}^{2} = {r}^{2}$

where (a , b ) are the coordinates of the centre and r = radius .

in this question (a , b ) = (2 , -5 ) and r =3

( substituting these values into the standard form equation )

$\Rightarrow {\left(x - 2\right)}^{2} + {\left(y + 5\right)}^{2} = 9$