Question 464886
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Hi,
Standard Form of an Equation of a Circle is {{{(x-h)^2 + (y-k)^2 = r^2}}} 
where Pt(h,k) is the center and r is the radius

x^2 - 4x  + y^2 - 4y + 4 = 12  |Completing square to put into standard form
(x-2)^2 - 4 +(y-2)^2 - 4 + 4 = 12
(x-2)^2 + (y-2)^2 = 16
Circle with C(2,2) and radius of 4