Definition:Quadrilateral

Definition
A quadrilateral is a polygon with exactly four sides.



Because it is a polygon, it follows that it also has four vertices.

Further subclassifications
Various breeds of irregular quadrilateral are unofficially and informally recognised:

Also known as
A quadrilateral can also (rarely) be found referred to as a tetragon.

Linguistic Note
The word quadrilateral derives from the Latin for four sides.

Similarly, the word tetragon derives from the Greek for four sides.