Parallelogram

A parallelogram is a 4-sided polygon with opposite sides parallel.

It has the following properties:

• Opposite sides are equal
• Diagonals bisect each other
• Opposite angles are equal
• Adjacent angles sum to 180⁰
• It has rotational symmetry of order at least 2.
• Its area is equal to its base multiplied by its vertical height

The set of rhombuses (rhombi) is a subset of the set parallelograms.