If the centroid of an equilateral triangle is (1, 1) and its one vertex is (-1, 2), then the equation of its circumcircle is
x2+y2−2x−2y−3=0
x2+y2−2x−2y−3=0
Fig.
The centre of the circumcircle is (1, 1).
Radius of the circumcircle
=√(1+1)2+(1−2)2=√5
∴ Equation of the circle :
(x−1)2+(y−2)2=5
⇒x2+y2−2x−2y−3=0