If a vertex of a triangle is (1,1) and the mid points of two sides through this vertex are (– 1, 2) and (3,2), then centroid of the triangle is
(1, 7/3)
1/3, 7/3
-1, 7/3
-1/3, 7/3
Let (x1, y1) and (x2, y2) be the other two vertices of the triangle, then x1+12=−1, y1+12=2⇒x1,y1=(−3,3); similarly x2,y2=(5,3)
centroid of the triangle is 1−3+53,1+3+33=(1,7/3)