Editing Rhomboid (section)

{{Short description|Geometrical concept}}
{{more citations needed|date=September 2012}}
{{about|the two-dimensional figure|the three-dimensional shape|Rhombohedron|the human back muscles|Rhomboid muscles}}

{{mergeto|Parallelogram|date=March 2025}}
{{Infobox polygon
| name        = Rhomboid 
| image       = Parallelogram.svg
| caption     = A rhomboid is a [[parallelogram]] with two edge lengths and no right angles
| type        = [[quadrilateral]], [[trapezoid|trapezium]]
| edges       = 4
| symmetry    = [[Point reflection|C<sub>2</sub>]], [2]<sup>+</sup>, 
| area        = ''b'' × ''h'' (base × height);<br>''ab'' sin ''θ'' (product of adjacent sides and sine of the vertex angle determined by them)
| properties  = [[convex polygon|convex]]}}

Traditionally, in two-dimensional [[geometry]], a '''rhomboid''' is a [[parallelogram]] in which adjacent sides are of unequal lengths and angles are [[Angle#Types of angles|non-right angled]]. 

The terms "rhomboid" and "parallelogram" are often erroneously conflated with each other (i.e, when most people refer to a "parallelogram" they almost always mean a rhomboid, a specific subtype of parallelogram); however, while all rhomboids are parallelograms, not all parallelograms are rhomboids.

A parallelogram with sides of equal length ([[equilateral]]) is called a ''[[rhombus]]'' but not a rhomboid.
A parallelogram with [[right angle]]d corners is a ''[[rectangle]]'' but not a rhomboid. 
A parallelogram is a rhomboid if it is neither a rhombus nor a rectangle.