What Is a Quadrilateral?

A quadrilateral is a figure with four sides and four corners.

There are many different types of quadrilaterals. Some quadrilaterals have sides of equal lengths. Other quadrilaterals have sides of different lengths. Some quadrilaterals have all equal angles, and other quadrilaterals have differently sized angles. You will learn to compute the area and perimeter of squares, rectangles, parallelograms, rhombuses and trapezoids.

You find the perimeter of quadrilaterals by measuring the length of each side and adding them together.

If you add all the angles in a quadrilateral, you will always get $360$${}^{\circ }$.