Rhomboid

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Rhomboid" – news · newspapers · books · scholar · JSTOR (September 2012) (Learn how and when to remove this message)

Rhomboid
A rhomboid is a parallelogram with two edge lengths and no right angles
Type	quadrilateral, trapezium
Edges and vertices	4
Symmetry group	C2, [2]+,
Area	b × h (base × height); ab sin θ (product of adjacent sides and sine of the vertex angle determined by them)
Properties	convex

Traditionally, in two-dimensional geometry, a rhomboid is a parallelogram in which adjacent sides are of unequal lengths and angles are 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 a rhombus but not a rhomboid.

A parallelogram with right angled corners is a rectangle but not a rhomboid.

The term rhomboid is now more often used for a rhombohedron or a more general parallelepiped, a solid figure with six faces in which each face is a parallelogram and pairs of opposite faces lie in parallel planes. Some crystals are formed in three-dimensional rhomboids. This solid is also sometimes called a rhombic prism. The term occurs frequently in science terminology referring to both its two- and three-dimensional meaning.