Question

Verify that points P (-2, 2), Q (2, 2) and R (2, 7) are vertices of a right angled triangle.

Answer 1

Distance between two points

Consider, PQ² + QR² = 42 + 52 = 16 + 25 = 41 …

[From (i) and (ii)]

∴ PR² = PQ² + QR² … [From (iii)]

∴ ∆PQR is a right angled triangle. … [Converse of Pythagoras theorem] 

∴ Points P, Q and R are the vertices of a right angled triangle.