A quadrilateral ABCD is drawn in which the mid points of sides AB, BC, CD and AD are P, Q, R and S respectively.
If quadrilateral ABCD is a parallelogram, what can you say about quadrilateral PQRS ?
Parallelogram
SP = 12BD ------------------ I
QR = 12BD ------------------ II
PQ = 12AC ------------------ III
RS = 12AC ------------------ IV
Therefore, SP = QR (from I and II)
PQ = RS (from III and IV)
Therefore, opposite sides are equal and parallel. So, PQRS is a parallelogram.
We need to check whether opposite angles are of 900 to determine if PQRS is a rectangle or a rhombus.
Since RS || AC and QR || BD, ∠AOB = ∠SRQ
We know that diagonals AC and BD bisect each other and do not intersect at right angles.
Therefore, PQRS is just a parallelogram.