*Kiddle Encyclopedia.*

# Parallelogram facts for kids

A **parallelogram** is a polygon with four sides (a quadrilateral). It has two pairs of parallel sides (sides which never meet) and four edges. The opposite sides of a parallelogram have the same length (they are equally long). The word "parallelogram" comes from the Greek word "parallelogrammon" (*bounded by parallel lines*). Rectangles, rhombuses, and squares are all parallelograms.

As shown in the picture on the right, because triangles * ABE* and

*are congruent (have the same shape and size),*

**CDE**In all Parallelogram's opposite angles are equal to each other. Angles which are not opposite in the Parallelogram will add up to 180 degrees.

## Characterizations

A simple (non self-intersecting) quadrilateral is a parallelogram if and only if __any one__ of the following statements is true:

- Two pairs of opposite sides are equal in length
- Two pairs of opposite angles are equal in measure
- The diagonals bisect each other
- One pair of opposite sides are parallel and equal in length
- Adjacent angles are supplementary
- Each diagonal divides the quadrilateral into two congruent triangles
- The sum of the squares of the sides equals the sum of the squares of the diagonals. (This is the parallelogram law)
- It has rotational symmetry of order 2
- It has two lines of symmetry

## Properties

- Opposite sides of parallelogram are parallel.
- Any line through the midpoint of a parallelogram bisects the area.
- Parallelograms are quadrilaterals.