First find the coordinate of the center:
(1,2)
Then find the value pf the radio, which is the distance
from the center to the perimeter:
r = 4.
Given center (s,t) and radius r, the formula o the equation is the following
[tex](x-s)^2+(y-t)^2=r^2[/tex]
We deduce the equation:
[tex](x-1)^2+(y-2)^2=16[/tex]
