**The quadrilateral formed by joining the mid-points of the sides of a quadrilateral PQRS, taken in order, is a rectanlge if**

**(a) PQRS is a parallelogram**

**(b) PQRS is a rectangle**

**(c) the diagonals of PQRS are perpendicular to each other**

**(d) the diagonals of PQRS are equal.**

**Solution:**

A, B, C and D are the mid-points of the sides PQ, QR, RS and SP respectively

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