2DEntfaltungen
2DEntfaltungen, or two-dimensional unfoldings, refer to methods for representing a surface or solid in the plane. In geometry, the term is most commonly associated with nets: a two-dimensional arrangement of polygons connected along edges that can be folded to form a three-dimensional polyhedron. For example, a cube has 11 distinct nets, and general results show that every convex polyhedron possesses at least one net, although counting all nets is a complex combinatorial problem.
Unfolding of curved surfaces extends this idea to non-planar geometries. Cylinders and cones can be developed
Beyond classical geometry, two-dimensional unfoldings appear in computer graphics, material fabrication, and origami design, where flat
History and usage: The study of polyhedral nets and geometric unfoldings has roots in classical geometry and
See also: net (polyhedron), development (geometry), unfolding (differential geometry).