## Rhombuses

##### Definition of a rhombus

- A rhombus is a quadrilateral with all sides equal.

##### Properties of a rhombus

- The opposite sides of a rhombus are parallel.
- The opposite angles of a rhombus are equal.
- The diagonals of a rhombus bisect each vertex angle.
- The diagonals of a rhombus bisect each other at right angles.

##### Tests for a rhombus

A quadrilateral is a rhombus if:

- it is a parallelogram, and a pair of adjacent sides are equal, or
- its diagonals bisect each other at right angles, or
- its diagonals bisect each vertex angle.