# Rhombus

rhombus
Twa rhombi.
Edges an vertices 4
Schläfli seembol { } + { } or 2{ }
Coxeter diagram
Symmetry group Dih2, [2], (*22), order 4
Aurie $\tfrac{pq}{2}$
Dual polygon rectangle
Properties convex, isotoxal

In Euclidean geometry, a rhombus (◊), plural rhombi or rhombuses, is a simple (non-self-intersectin) quadrilateral whose fower sides aw hae the same length. Anither name is equilateral quadrilateral, syne equilateral means that aw o its sides are equal in length. The rhombus is eften cried a diamond, efter the diamonds suit in playing cards, or a lozenge, tho the umwhile sometimes refers specifically tae a rhombus wi a 60° angle (see Polyiamond), an the latter sometimes refers specifically tae a rhombus wi a 45° angle.

Every rhombus is a parallelogram, an a rhombus wi richt angles is a square. [1][2]

## References

1. Note: Euclid's oreeginal defineetion an some Inglish dictionaries' defineetion o rhombus excludes squares, but modren mathematicians prefer the inclusive defineetion.
2. inclusive usage