quadrilateral

/kwɑdrɪˈlæɾərəl/

/kwɒdrɪˈlætərəl/

Other forms: quadrilaterals; quadrilaterally

A quadrilateral is a four-sided polygon, like a square, rectangle, or rhombus. The computer screen you are looking at right now is probably in the shape of a quadrilateral.

The quadrilateral is a shape you'll learn about in geometry. Quadrilaterals include more than one type of shape, but all quadrilaterals have four sides. The most common type of quadrilateral is the square, but rectangles and rhombuses are quadrilaterals too. Quadrilaterals are also called quadrangles and tetragons. When you see the word quadrilateral, think "four sides".

Definitions of quadrilateral

1. noun

   a four-sided polygon
   synonyms: quadrangle, tetragon

   types:

   parallelogram

   a quadrilateral whose opposite sides are both parallel and equal in length

   trapezium

   a quadrilateral with no parallel sides

   trapezoid

   a quadrilateral with one pair of parallel sides

   diamond, lozenge, rhomb, rhombus

   a parallelogram with four equal sides; an oblique-angled equilateral parallelogram

   rhomboid

   a parallelogram with adjacent sides of unequal lengths; an oblique-angled parallelogram with only the opposite sides equal

   rectangle

   a parallelogram with four right angles

   type of:

   polygon, polygonal shape

   a closed plane figure bounded by straight sides
2. adjective

   having four sides
   synonyms: four-sided

   many-sided, multilateral

   having many parts or sides