# What Is a Parallelogram?

## What Is a Parallelogram?

A paralleogram is a four sided shape with opposite sides parallel and equal in length. ### Dictionary Definition

The Oxford English Dictionary defines a parallelogram as "a four-sided plane rectilinear figure whose opposite sides are parallel; especially one whose sides do not intersect at right angles."

## Properties of Parallelograms

• Opposite sides of a parallelogram are parallel. • Opposite sides of a parallelogram are of equal length. • Opposite angles of a parallelogram are equal. • Adjacent angles of a parallelogram add up to 180°. They are supplementary angles. • All angles of a parallelogram add up to 360°. • The diagonals of a parallelogram bisect each other. The diagonals cross each other half-way along their lengths. ### The Perimeter of a Parallelogram

The perimeter of a parallelogram is given by the formula: In this formula, b is the length of the base and s is the length of the side of the parallelogram.

### The Area of a Parallelogram

The area of a parallelogram is given by the formula: In this formula, b is the length of the base and h is the height of the parallelogram.

Read more about how to find the area of a parallelogram

What is an angle? What are supplementary angles? Finding the area of a parallelogram What is a polygon? What are the interior angles of a polygon? Finding the sum of the interior angles of a polygon Learn about parallelograms ( interactive widget)