What is the name for a geometric figure with four sides and four angles?

A geometric figure with four sides and four angles is called a quadrilateral. The name comes from Latin: quadri means “four,” and latus means “side.” In modern geometry, a quadrilateral is a polygon made from four line segments joined end to end, creating four vertices and four interior angles.

Quadrilaterals can have many different appearances. A square has four equal sides and four right angles, while a rectangle has four right angles but only opposite sides must be equal. Rhombuses have four equal sides, parallelograms have two pairs of parallel sides, and trapezoids have at least one pair of parallel sides.

A common mix-up is assuming every quadrilateral must look like a square or rectangle. It may instead be slanted, irregular, concave, or even self-intersecting in some classifications. For a simple quadrilateral drawn on a flat plane, the interior angles add up to 360 degrees. “Tetragon” and “quadrangle” are also accepted mathematical terms, but quadrilateral is the standard general term.