Let's start by recalling the standard form of an equation of a circle.
(x- h)^2+(y- k)^2= r^2
In this form, ( h, k) is the center of the circle and r is its radius.
Looking at the graph, we can see that the center of the circle is ( 0, - 2) and its radius is 3.
This information is enough to write the equation.
(x- 0)^2+(y-( - 2))^2= 3^2
⇕
x^2+(y+2)^2=9
