P and Q are points on opposite sides AD and BC of a parallelogram ABCD such that PQ passes through the point of intersection O of its diagonals AC and BD. Show that PQ is bisected at O.
Solution.
Given: ABCD is a parallelogram whose diagonals bisect each other at O.
To Prove: PQ is bisected at O.
Proof: In and
{Vertically opposite angles}
{interior angles}
OB = OD {given}
{by ASA congruence}
OP = OQ {by CPCT rule}
So, PQ is bisected at O