

InterviewSolution
1. |
In figure. ABCD is a parallelogram. P and Q are the mid-points of opposite sides AB and DC of a parallelogram ABCD. Prove that PRQS is a parallelogram. |
Answer» Given: ABCD is a parallelogram. P and Q are respectively the mid-points of opposite sides AB and DC of a parallelogram ABCD. AQ and DP are joined intersecting in S and CP and BQ are joined intersecting in R. To prove: Quadrilateral PQRS is a parallelogram. Proof: ∵ ABCD is a parallelogram. ∴ AB = DC and AB || DC ⇒ \(\frac { 1 }{ 2 }\)AB = \(\frac { 1 }{ 2 }\)DC ⇒ AP = QC and AP || QC ⇒ APCQ is a parallelogram. Similarly. PBQD is also a parallelogram. Since in parallelogram APCQ. AQ || PC (opposite sides of a parallelogram) ∴ SQ || PR Now in parallelogram PBQD PD || BQ ∴ SP || QR Now in quadrilateral PRQS, SQ || PR and SP || QR. Therefore, PRQS is a parallelogram. Hence proved. |
|