Properties of a Parallelogram

A diagonal of a parallelogram divides it into two congruent triangles.
In a parallelogram, opposite sides are equal.
If each pair of opposite side of a quadrilateral is equal then it is a parallelogram.
In a parallelogram, opposite angles are equal.
If in a quadrilateral, each pair of opposite angles is equal, then it is a parallelogram.
The diagonals of a parallelogram bisect each other.
if the diagonals of a quadrilateral bisect each other, then it is a parallelogram.
A quadrilateral is a parallelogram, if a pair of sides is equal and parallel