# A circle has the equation (x+1)^2+(y-3)^2=16. What are the coordinates of its center and length of its radius?

The center is C=(-1;3) the radius is $r = 4$
The equation is in form of ${\left(x - a\right)}^{2} + {\left(y - b\right)}^{2} = {r}^{2}$, so the coordinates and the radius are:
$C = \left(a , b\right)$, radius $r$