Quadrilaterals

A quadrilateral is a polygon with four sides and four internal angles. There are many different types of quadrilateral. Look at the picture below. It shows six different quadrilaterals.

Types of Quadrilateral

Rectangle: The opposite sides of a rectangle are parallel and equal in length. The four internal angles of a rectangle are all right angles (90°). How many rectangles can you see in the image above?

Square: All four sides of a square are equal in length. The opposite sides are parallel. The four internal angles of a square are all right angles (90°). Please note that all squares are also rectangles. However, not all rectangles are squares. Do you see any squares in the picture above?

Rhombus: A rhombus has four equal sides. The opposite angles of a rhombus are also equal. The opposite sides are parallel. The yellow shape in the image above is a rhombus. A square is also a rhombus. However, not every rhombus is a square.

Parallelogram: The opposite sides of a parallelogram are parallel to each other. The opposite sides are also the same length. In the picture above, the purple shape is a parallelogram. Squares and rectangles are parallelograms as well. A rhombus is also a parallelogram.

Trapezoid: A trapezoid is a quadrilateral with one pair of sides that are parallel. The blue shape in the picture above is a trapezoid.

Note: Any four sided polygon is a quadrilateral. Some quadrilaterals, like the red shape in the picture, do not fit into any of the categories above.