# Identifying Quadrilaterals

**Quadrilaterals are four-sided, two-dimensional figures.** We classify quadrilaterals based upon:

- Whether or not the sides (1 pair or both pairs) are
**parallel**; - Whether or not the sides are
**equal**; - Whether or not the angles are
**right angles**.

Some quadrilaterals are just quadrilaterals (they belong to no more specific categories). Other quadrilaterals belong to many quadrilateral categories (e.g., a square is a rectangle, a rhombus, a parallelogram, and a quadrilateral!).

Use the flow chart below to see how to categorize quadrilaterals: