Find the centroid of the triangle with vertices A(x1,y1), B(x2,y2) and C(x3,y3).
Prove that the coordinates of the centroid of the triangle whose vertices are (x1,y1),(x2,y2) and (x3,y3) are (x1+x2+x33,y1+y2+y33) and also, deduce that the medians of a triangles are concurrent.
ABCD is a parallelogram with vertices A (X1, Y1) , B(X2, Y2) and C (X3, Y3). Then the coordinates of the fourth vertex D in terms of the coordinates of A, B and C are