Rhombus

In geometry, a rhombus (: 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 rhimbus 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. Provided by Wikipedia