Question

If three consecutive vertices of a parallelogram are (1, -2), (3, 6) and (5, 10), find its fourth vertex.

Answer 1

Let A(1, -2), B(3, 6) and C(5, 10) and D(x,y) be the given points taken in order.

Since, diagonals of parallelogram bisect each other

Coordinates of mid-point of AC = Coordinates of midpoint of BD

Hence, the fourth vertex is (3,2)