key term - Quadrilateral

Definition

A quadrilateral is a polygon with four sides. It is characterized by having four vertices (corners) and four angles.

Related terms

Polygon: A polygon is any closed figure with straight sides. Quadrilaterals are one type of polygon.

Parallelogram: A parallelogram is a special type of quadrilateral where opposite sides are parallel.

Trapezoid: A trapezoid is another type of quadrilateral with only one pair of parallel sides.