## Saturday, 9 August 2014

### chapter 2 Quadrilaterals and Parallelograms

Theorem $5$
The opposite sides and opposite interior angles of a parallelogram are equal.
Theorem $5a$
If a quadrilateral has opposite sides equal then it is a parallelogram.
Theorem $5b$
If a quadrilateral has opposite interior angles equal then it is a parallelogram.
Theorem $6$
The diagonals of a parallelogram bisect each other.
Theorem $7$
The diagonals of a rhombus are perpendicular.