# A circle is centered at the point (3.2, 2.1), and has a radius of length 4.3. What is its equation?

Oct 3, 2016

${\left(x - 3.2\right)}^{2} + {\left(y - 2.1\right)}^{2} = 18.49$

#### Explanation:

The equation of a circle is ${\left(x - h\right)}^{2} + {\left(y - k\right)}^{2} = {r}^{2}$

where $\left(h , k\right)$ is the center of the circle and $r$ is the radius.

$\left(h , k\right) = \left(3.2 , 2.1\right)$ and $r = 4.3$

Substituting gives:

${\left(x - 3.2\right)}^{2} + {\left(y - 2.1\right)}^{2} = {4.3}^{2}$

${\left(x - 3.2\right)}^{2} + {\left(y - 2.1\right)}^{2} = 18.49$