# Quadrilateral A **quadrilateral** is a [[polygon]] with four sides. ## Types of Quadrilateral * [[Square]] * [[Rectangle]] * [[Rhombus]] * [[Parallelogram]] * [[Trapezium]] * [[Kite]] * [[Dart]] ## Interior Angles of a Quadrilateral Using the formula for the [[interior angles of a polygon]], the interior angles of a quadrilateral add up to $360^\circ$. ## Tessellation Properties A consequence of the fact that the interior angles of a quadrilateral add up to $360^\circ$ is that any quadrilateral will [[tessellate]] the plane. +-- {: .image} [[QuadrilateralTesselation.png:pic]] =-- With the vertices of the quadrilateral labelled $A$, $B$, $C$, $D$ as above, the neighbouring quadrilateral along the edge $A B$ is obtained by reflecting the quadrilateral and then aligning the edge $B A$ of the reflection along the edge $A B$ of the original. At each vertex this brings one copy of each interior angle and the tessellation then follows from the fact that these angles sum to $360^\circ$. [[!redirects quadrilaterals]] [[!redirects interior angles in a quadrilateral]] [[!redirects interior angles of a quadrilateral]] [[!redirects angles in a quadrilateral]]