Folded structures in the plane are the structures in which all the highest points of the
elements and all the elements of the lowest points of the folded structure belong to two
parallel planes.
Frame folded structures represent constructional set in which the elements of each
segment of the folds mutually occupy a frame spatial form. This type of folded structure is
spatial organization of two or more folds in the plane.
Spatial folded structures are the type of a structure in which a spatial constructive set
is formed by combining mutually the elements of a folded structure.