Library/Geometry/Plane geometry/Quadrilaterals/Quadrilaterals (other)

Quadrilaterals (other)

Overview
Important

Quadrilaterals that do not meet the criteria for being parallelograms, rectangles, squares, rhombuses, or trapeziums are called general or irregular quadrilaterals. Their sides and angles can all be different.

Important properties

  • The sum of the interior angles of any quadrilateral is 360 degrees.

  • Irregular quadrilaterals have no special symmetry or parallel sides.

  • They can be convex (all angles less than 180°) or concave (one angle greater than 180°).

  • No sides or angles are required to be equal.