P and Q are the mid-points of the opposite sides AB and CD of a parallelogram ABCD. AQ intersects DP at S and BQ intersects CP at R. Show that PRQS is a parallelogram.
Solution.
Given: ABCD is a parallelogram, P and Q are the mid-points of AB and CD
To Prove: PRQS is a parallelogram.
Proof: Since ABCD is a parallelogram
Also, AB = DC …..(1)
{dividing by 2}
{P and Q are the mid-points of AB and DC}
As, and
Thus APCQ is a parallelogram
or …..(2)
or
{dividing both sides by 2}
{P and Q are the mid-points of AB and DC}
and
So, BPDQ is a parallelogram
or …..(3)
From equation 2 and 3
and
So, PRQS is a parallelogram.
Hence Proved