Title
Unfoldings of an envelope
Abstract
An envelope is equivalent to a rectangle dihedron or a doubly-covered rectangle. It is cut along a tree graph that spans the four corners of the envelope to get a planar region. We show in Theorem 1 that every region satisfies the Conway criterion and so copies of the region tile the plane using only translations and 180° rotations. Let P1 and P2 be two regions obtained by unfolding the same envelope along two non-crossing trees, respectively. Then we show in Theorem 2 that P1 is equi-rotational into P2, which means that P1 can be dissected into pieces that are hinged at corners, so that the pieces can be rigidly transformed into P2 by monotonous rotations at the hinges. In Theorem 3, Theorem 4, we give the sufficient conditions for Conway tiles to be foldable into envelopes.
Year
DOI
Venue
2019
10.1016/j.ejc.2018.02.023
European Journal of Combinatorics
Field
DocType
Volume
Discrete mathematics,Combinatorics,Tree (graph theory),Dihedron,Rectangle,Planar,Hinge,Tile,Mathematics,Conway criterion
Journal
80
ISSN
Citations 
PageRank 
0195-6698
0
0.34
References 
Authors
4
2
Name
Order
Citations
PageRank
Jin Akiyama1103.25
Kiyoko Matsunaga241.26