# Which is the equation of a circle with center (0,1) and radius 2 units?

Jul 1, 2018

${x}^{2} + {\left(y - 1\right)}^{2} = 4$

#### Explanation:

Given: circle with center $\left(0 , 1\right)$ and $r = 2$

The standard equation for a circle is (x - h)^2 + (y - k)^2 = r^

where $\text{center} \left(h , k\right)$ and $r = \text{radius}$

${\left(x - 0\right)}^{2} + {\left(y - 1\right)}^{2} = 4$

Since $x - 0 = x , \text{ } {x}^{2} + {\left(y - 1\right)}^{2} = 4$