Rhomboid

Rhomboid
A rhomboid is a parallelogram with two edge lengths and no right angles
Typequadrilateral, trapezium
Edges and vertices4
Symmetry groupC2, [2]+,
Areab × h (base × height);
ab sin θ (product of adjacent sides and sine of the vertex angle determined by them)
Propertiesconvex

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