What is a quadrilateral? The key to a quadrilateral is found in its name, “quad" meaning four and “lateral" meaning side. So a quadrilateral is a four sided polygon. Some common examples are kites, parallelograms, trapezoids, rhombuses, rectangles, and squares.

The following video goes over the properties of a Quadrilateral

• Four Sided

• Closed figure

• Four vertices (also known as corners)

• Interior angles add up to 360◦

• Straight sides, no curves

Two diagonals

Quadrilaterals can be subdivided into parallelograms and trapezoids. Let’s look at parallelograms. Some common examples of parallelograms are rectangles, rhombuses, and squares. They all have opposite sides that are parallel and congruent, and diagonals that bisect each other.

Trapezoids have exactly one pair of parallel sides. The perimeter of a trapezoid is the sum of four side lengths and the area is one half times base one plus base two times height. The perimeter and area of each quadrilateral varies according to its shape. Here is a link to the perimeter and area formulas for most quadrilaterals.