In geometry, a **rhombus** is a quadrilateral whose four sides are of equal length. It is a special case of the parallelogram; a rhombus with right angles is a square.

Rhombi hold the following properties:

- All four sides are of equal length (congruent)
- Opposite sides are parallel to one another
- Parallelogram

- Opposite angles are of equal measure (congruent)
- Adjacent angles are supplementary to one another
- Diagonals bisect the angles of the corners they connect
- Diagonals bisect one another
- Diagonals intersect at right angles