(Mathématiques) Polygone ŕ quatre côtés.
ETYM French, from Latin quadrangulum; quattuor four + angulus an angle. Related to Four, and Angle a corner.
1. A plane figure having four angles, and consequently four sides; any figure having four angles.
2. A square or quadrangular space or inclosure, such a space or court surrounded by buildings, esp. such a court in a college or university.
Plane (two-dimensional) figure with four straight sides. The following are all quadrilaterals, each with distinguishing properties: square with four equal angles and sides, four axes of symmetry; rectangle with four equal angles, opposite sides equal, two axes of symmetry; rhombus with four equal sides, two axes of symmetry; parallelogram with two pairs of parallel sides, rotational symmetry; and trapezium one pair of parallel sides.
A four-sided polygon; SYN. quadrangle, tetragon.