Name a quadrilateral whose diagonals bisect each other.

The lengths of diagonals of a rhombus are $6 \mathrm{cm}$ and $8 \mathrm{cm}$. Is it a square? If no, give reasons.

State whether the following statements are true or false and correct the false statement:

Every rectangle is a parallelogram.

Every parallelogram is a rhombus.

Every rectangle is a square.

State whether the following statements are true or false and correct the false statement:

Parallel sides of an isosceles trapezium are equal.

State whether the following statements are true or false and correct the false statement:

In a parallelogram opposite sides are parallel but may not be equal.