foursided

Foursided is a term used to describe objects that have four sides. In geometry, a four-sided figure is called a quadrilateral, a polygon whose interior angles sum to 360 degrees. Quadrilaterals are diverse and include shapes such as squares, rectangles, rhombi, parallelograms, trapezoids, and kites. They can be convex, with all interior angles less than 180 degrees, or concave, where one or more interior angles exceed 180 degrees. The diagonals of quadrilaterals vary in length and intersection properties depending on the specific type.

Classification and properties of quadrilaterals form a core part of the study of four-sided figures. They can be described by their sides or their angles. By sides, common categories include equilateral quadrilaterals (all sides equal) and isosceles varieties (opposite sides equal). By angles, categories include right-angled quadrilaterals (having at least one 90-degree angle) and general cases without right angles. Other notable types include trapezoids (one pair of parallel sides), parallelograms (both pairs of opposite sides are parallel), rhombi (all sides equal), and kites (two distinct pairs of adjacent equal sides).

In design, architecture, and computer graphics, four-sided layouts and grids are prevalent because they tessellate well and align with common construction techniques. The concept of foursided can also appear as a brand name, project title, or cultural reference, used to evoke symmetry, balance, or modularity.

See also: quadrilateral, polygon, parallelogram.