A quadrilateral has four angles. There are many different types of quadrilaterals, and each has a specific name based on the shape that is formed.
A quadrilateral can be named based off of the lengths of the sides and what type of angles are formed in the interior. A square is a quadrilateral with four equal sides and all interior angles equaling 90 degrees each. A rectangle is a quadrilateral that has interior angles that each equal 90 degrees, but all sides are not the same length. A rhombus is a quadrilateral that has interior angles that are equal, but they are not 90 degrees. The sides are also all the same length.