Without using distance formula, show that points (– 2, – 1), (4, 0), (3, 3) and (–3, 2) are the vertices of a parallelogram.
Solution:
Let the vertices be A(-2, -1), B(4, 0), C(3, 3), D(-3, 2)
Now mAB = mCD ⇒ AB || CD
and mBC = *** ⇒ BC || AD
Hence ABCD is a parallelogram.