If the centroid of an equilateral triangle . (2, - 2) and its one
vertex is (-1, 1), then the equation of
circumcircle is
x2+y2−4x+4y−10=0
x2+y2+4x−4y+10=
x2+y2+4x−4y−10=0
x2+y2−4x+4y+10=
Circumcircle of the equilateral triangle has
centre at(2, - 2) and passes through(-1, 1). So, its equation is
(x−2)2+(y+2)2=(2+1)2+(−2−1)2⇒x2+y2−4x+4y−10=0