first find the radius of circle by finding the length from center to the given point
well we need the square of radius r^2 = (6-2)^2 + (4-1)^2 = 25
equation of circle is (x - a)^2 + (y - b)^2 = r^2 where (a,b) is the center
so our circle is
(x - 6)^2 + ( y - 4)^2 = 25
