Hierarchy classification:

1. top of the aat hierarchies
2. Physical Attributes Facet
3. Attributes and Properties (hierarchy name)
4. [attributes and properties by specific type]
5. form attributes
6. shape (form attribute)
7. geometric shape
8. polygonal
9. quadrilateral (shape)

Anotations

Scope note:

In North America, having the form of quadrilateral figures with no parallel sides. In Britain and certain other places, "trapeziums" are the same as "trapezoids" in North America, that is, figures having one set of parallel lines.