Quadrilaterals

Concept sheet | Mathematics

What is a quadrilateral?

Definition

A quadrilateral is a polygon which has 4 sides.

There are different kinds of quadrilaterals. Their characteristics enable us to tell them apart.

Examples

Be careful!

There are other kinds of quadrilaterals without a specific name. They are called general quadrilaterals.

Examples:

What are the characteristics of a square?

The square is a convex polygon. Read the concept sheet Polygons to learn about convex polygons.
It has 2 pairs of parallel sides. Read the concept sheet Parallel and Perpendicular Lines to learn about parallel sides.
Its 4 sides are the same length (isometric).
It has 4 right angles. Read the concept sheet Angles to learn about right angles.

The rectangle is a convex polygon. Read the concept sheet Polygons to learn about convex polygons.
It has 2 pairs of parallel sides. Read the concept sheet Parallel and Perpendicular Lines to learn about parallel sides.
Its opposite sides are the same length (isometric).
It has 4 right angles. Read the concept sheet Angles to learn about right angles.

The rhombus is a convex polygon. See the concept sheet Polygons to learn about convex polygons.
It has 2 pairs of parallel sides. Read the concept sheet Parallel and Perpendicular Lines to learn about parallel sides.
Its 4 sides are the same length (isometric).
Its opposite angles are congruent (isometric).

The parallelogram is a convex polygon. Read the concept sheet Polygons to learn about convex polygons.
It has 2 pairs of parallel sides. Read the concept sheet Parallel and Perpendicular Lines to learn about parallel sides.
Its opposite sides are the same length (isometric).
Its opposite angles are congruent (isometric).

The trapezoid is a convex polygon. Read the concept sheet Polygons to learn about convex polygons.
It has 1 pair of parallel sides. Read the concept sheet Parallel and Perpendicular Lines to learn about parallel sides.