A quadrilateral is a polygon with four sides and four corners.

Quadrilaterals can also be called quadrangles (similar to triangle) or tetragons (similar to pentagon), though these names are not commonly used.

Types of Quadrilaterals

There are seven types of quadrilaterals, each with its own unique characteristics.

1. Trapezoid - a quadrilateral with exactly one pair of parallel sides.
2. Isosceles Trapezoid - a particular type of trapezoid whose legs are congruent.
3. Kite - a quadrilateral with two pairs of congruent consecutive sides, where opposite sides are not congruent.
4. Parallelogram - a quadrilateral with two pairs of parallel sides.
5. Rhombus - a type of parallelogram that has four equal side lengths.
6. Rectangle - a type of parallelogram that has four right angles
7. Square - a type of rectangle that has four equal side lengths.

Any quadrilateral that cannot be described by any of these names does not take a special name; they are only called quadrilaterals.

The diagram above illustrates each of the types of quadrilaterals and their relationship to one another.