WAEC Further Mathematics 2017 Theory question 107

Theory question 107

Coordinate Geometry

A parallelogram MNQR has vertices M(4, −6), N(10, 2), Q(8, 16) and R(x, y). Find the coordinates of R.

Show the model answer

Model answer

Diagonals MQ and NR bisect each other: M + Q = N + R.
R = (4 + 8 − 10, −6 + 16 − 2) = (2, 8).

Explanation

The diagonals of a parallelogram share a midpoint.