A quadrilateral ABCD is drawn in which the mid points of sides AB , BC , CD and AD are P,Q,R and S respectively. Solve the following questions.
If quadrilateral ABCD is a parallelogram , what can you say about quadrilateral PQRS ?
Parallelogram
Join the diagonals BD and AC of quadrilateral ABCD.
In ΔABD , SP || BD and SP = 12 BD (mid point theorem) ------- I
In ΔBCD , QR || BD and QR = 12BD (mid point theorem) ------- II
In ΔACD , RS || AC and RS = 12 AC (mid point theorem) -------- III
In ΔABC , PQ || AC and PQ = 12 AC (mid point theorem) ---------IV
From I and II , SP || QR and SP = QR ---------------------------------------- V
From III and IV , RS || PQ and RS = PQ ---------------------------------------- VI
From V and VI , PQRS is a parallelogram since opposite sides are equal and parallel.