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Related papers: Noncongruent equidissections of the plane

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We present a simplified proof of a forty-year-old result concerning the tiling of the plane with equilateral convex polygons. Our approach is based on a theorem by M. Rao, who used an exhaustive computer search to confirm the completeness…

Metric Geometry · Mathematics 2025-11-11 Bernhard Klaassen

Convex hexagons that can tile the plane have been classified into three types. For the generic cases (not necessarily convex) of the three types and two other special cases, we classify tilings of the plane under the assumption that all…

Combinatorics · Mathematics 2024-05-09 Xinlu Yu , Erxiao Wang , Min Yan

We consider a certain tiling problem of a planar region in which there are no long horizontal or vertical strips consisting of copies of the same tile. Intuitively speaking, we would like to create a dappled pattern with two or more kinds…

Discrete Mathematics · Computer Science 2018-12-18 Shizuo Kaji , Alexandre Derouet-Jourdan , Hiroyuki Ochiai

Congruent polygons are congruent in angles as well as in edge lengths. We concentrate on the angle aspect, and investigate how tilings of the sphere by congruent pentagons can be determined by the angle information only. We also investigate…

Combinatorics · Mathematics 2026-04-29 Robert Barish , Hoi Ping Luk , Min Yan

Inspired by the modelization of 2D materials systems, we characterize arrangements of identical nonflat squares in 3D. We prove that the fine geometry of such arrangements is completely characterized in terms of patterns of mutual…

Mathematical Physics · Physics 2021-08-05 Manuel Friedrich , Manuel Seitz , Ulisse Stefanelli

We develop the basic and new tools for classifying non-side-to-side tilings of the sphere by congruent triangles. Then we prove that, if the triangle has any irrational angle in degree, such tilings are: a sequence of 1-parameter families…

Combinatorics · Mathematics 2025-05-23 Wen Chen , Jinjin Liang , Erxiao Wang

A plane tiling consisting of congruent copies of a shape is isohedral provided that for any pair of copies, there exists a symmetry of the tiling mapping one copy to the other. We give a $O(n\log^2{n})$-time algorithm for deciding if a…

Computational Geometry · Computer Science 2016-03-10 Stefan Langerman , Andrew Winslow

An N -tiling of triangle ABC by triangle T is a way of writing ABC as a union of N triangles congruent to T, overlapping only at their boundaries. The triangle T is the "tile". The tile may or may not be similar to ABC . We wish to…

Metric Geometry · Mathematics 2012-06-12 Michael Beeson

We say that a triangle $T$ tiles a polygon $A$, if $A$ can be dissected into finitely many nonoverlapping triangles similar to $T$. We show that if $N>42$, then there are at most three nonsimilar triangles $T$ such that the angles of $T$…

Metric Geometry · Mathematics 2020-02-28 M. Laczkovich

In this paper we give a classification of tilings of the sphere by congruent quadrilaterals with exactly two equal edges. The tilings are the earth map tilings, $(p,q)$-earth map tilings and their flip modifications, and quadrilateral…

Combinatorics · Mathematics 2021-09-06 Ho Man Cheung , Hoi Ping Luk

Given a finite collection of two-dimensional tile types, the field of study concerned with covering the plane with tiles of these types exclusively has a long history, having enjoyed great prominence in the last six to seven decades. Much…

Statistical Mechanics · Physics 2024-12-24 Eduardo J. Aguilar , Valmir C. Barbosa , Raul Donangelo , Sergio R. Souza

An N -tiling of triangle ABC by triangle T is a way of writing ABC as a union of N triangles congruent to T, overlapping only at their boundaries. The triangle T is the "tile'". The tile may or may not be similar to ABC . This paper is the…

Metric Geometry · Mathematics 2012-06-12 Michael Beeson

A group-theoretical approach to the construction of quasiperiodic tilings of a Euclidean plane, possessing five-fold symmetry, is applied. Of the infinitely many of variants of quasiperiodic partitions of the plane, possessing the dihedral…

General Mathematics · Mathematics 2019-08-08 Alexander S. Prokhoda

A tiling is a decomposition of a polygon into finitely many non-overlapping triangles. We prove that if a regular n-gon, $n \geq 5$, $n \neq 28$, can be tiled with similar right triangles, then one of the angles of these triangles is in…

Combinatorics · Mathematics 2021-02-23 Ivan Vasenov

We show that the following problem is undecidable: given two polygonal prototiles, determine whether the plane can be tiled with rotated and translated copies of them. This improves a result of Demaine and Langerman [SoCG 2025], who showed…

Computational Geometry · Computer Science 2025-06-16 Jack Stade

An N-tiling of triangle ABC by triangle T is a way of writing ABC as a union of N triangles congruent to T, overlapping only at their boundaries. The triangle T is the "tile". The tile may or may not be similar to ABC. In this paper we…

Metric Geometry · Mathematics 2026-05-05 Michael Beeson

A first step in investigating colour symmetries of periodic and nonperiodic patterns is determining the number of colours which allow perfect colourings of the pattern under consideration. A perfect colouring is one where each symmetry of…

Combinatorics · Mathematics 2008-07-30 Dirk Frettlöh

An equilateral triangle cannot be dissected into finitely many mutually incongruent equilateral triangles [Tutte 1948]. Therefore Tuza [Tuza 1991] asked for the largest number $s=s(n)$ such that there is a tiling of an equilateral triangle…

Metric Geometry · Mathematics 2019-03-26 Christian Richter

Aperiodic tilings are non-periodic tilings defined by local rules. They are widely used to model quasicrystals, and a central question is to understand which of the non-periodic tilings are actually aperiodic. Among tilings, those by rhombi…

Dynamical Systems · Mathematics 2015-09-24 Nicolas Bédaride , Thomas Fernique

The Heesch problem 'grades' polygons that fail to tile the plane in terms of the number of layers (or corollas) of copies of it that can be formed around a central unit. We study the different topology of ' walls', which we define to be…

History and Overview · Mathematics 2016-06-01 Erich Friedman , R. Nandakumar