A quadrilateral is a geometric shape that consists of four straight sides and four angles. The sum of the internal angles in a quadrilateral always equals 360 degrees.
Common examples of quadrilaterals include rectangles, squares, parallelograms, and trapezoids. Each type of quadrilateral has its unique properties and characteristics.
For instance, rectangles have four right angles, squares have four equal sides and four right angles, parallelograms have opposite sides that are parallel, and trapezoids have one pair of parallel sides.
Quadrilaterals are fundamental shapes used in geometry for various calculations and constructions.