Answer
Center $(1, 2)$
Radius = $3$ units
Work Step by Step
RECALL:
The circle whose equation is of the form $(x-h)^2 + (y-k)^2=r^2$ has its center at $(h, k)$ and has a radius of $r$ units.
Thus, the given circle has:
center at (1, 2)
radius = $\sqrt9 = 3$