In Euclidean geometry, a rhombus(◊), plural rhombi or rhombuses, is a simple (non-self-intersecting) quadrilateral whose four sides all have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length. The rhombus is often called a diamond, after the diamonds suit in playing cards which resembles the projection of an octahedral diamond, or a lozenge, though the former sometimes refers specifically to a rhombus with a 60° angle (see Polyiamond), and the latter sometimes refers specifically to a rhombus with a 45° angle.

Every rhombus is a parallelogram and a kite. A rhombus with right angles is a square.

Etymology

The word "rhombus" comes from Greek ῥόμβος(rhombos), meaning something that spins, which derives from the verb ρέμβω (rhembō), meaning "to turn round and round". The word was used both by Euclid and Archimedes, who used the term "solid rhombus" for two right circular cones sharing a common base.

Characterizations

Rhombus may refer to:

Rhombus are a dub/drum n bass/reggae/roots band from Wellington, New Zealand.

They were formed in 2001 by Thomas Voyce and Simon Rycroft, later joined by Ahmen Mahal aka Imon Star (who departed from the group in 2007 to pursue his solo project 'Olmecha Supreme') and Koa Williams (Roots Foundation Sound System founding member). The band has toured extensively in their native New Zealand along with a few international dates, notably in Japan (2002) and in Australia, playing twice at the Sydney Opera House in November 2004. Over the years they have performed with such acts as St Germain (France), Fat Freddy's Drop (NZ), Salmonella Dub (NZ), Michael Franti (USA), Dry & Heavy (Japan), Trinity Roots (NZ), Gomez (UK) Kora (NZ), Shapeshifter (NZ), Katchafire (NZ) and also performed at the Big Day Out (NZ) 2006.

The band have also given their time to a number of causes including Greenpeace, Tsunami Relief, SurfAid International, the Cancer Society, and the Peace Boat. Their travels on the Japanese-based global NGO Peace Boat have taken them through the Caribbean (including Jamaica, home of Studio One, King Tubby and many other influential dub and reggae artists), with the intent of "spreading the values of sustainability, co-operation and peace through music workshops from a chartered ship."