Rhombus

Rhombus
A rhombus in two different orientations
Type	quadrilateral, trapezoid, parallelogram, kite
Edges and vertices	4
Schläfli symbol	{ } + { } {2α}
Coxeter–Dynkin diagrams
Symmetry group	Dihedral (D2), [2], (*22), order 4
Area	${\displaystyle K={\frac {p\cdot q}{2}}}$ (half the product of the diagonals)
Properties	convex, isotoxal
Dual polygon	rectangle

In geometry, a rhombus (pl.: rhombi or rhombuses) is an equilateral quadrilateral, a quadrilateral whose four sides all have the same length. Other names for rhombus include diamond, lozenge, and calisson.

Every rhombus is a simple polygon (having no self-intersections). A rhombus is a special case of a parallelogram and a kite. A rhombus with right angles is a square. A non-square rhombus has two opposite acute angles and two opposite obtuse angles.