Regular Polytopes is a mathematical geometry book written by Canadian mathematician H.S.M. Coxeter. Originally written in 1947, the book was updated and republished in 1963 and 1973.
The book is a comprehensive survey of the geometry of regular polytopes, the generalisation of regular polygons and regular polyhedra to higher dimensions. Originating with an essay entitled Dimensional Analogy written in 1923, the first edition of the book took Coxeter 24 years to complete.
Coxeter starts by introducing two-dimensional polygons and three-dimensional polyhedra. He then gives a rigorous combinatorial definition of "regularity" and uses it to show that there are no other convex
regular polyhedra apart from the five Platonic solids
. The concept of "regularity" is extended to non-convex shapes such as star polygons
and star polyhedra
; to tessellations
and to polytopes in higher dimensions. Coxeter introduces and uses the groups of reflections that became known as Coxeter groups
The book combines algebraic rigour with clear explanations, many of which are illustrated with diagrams, and with a diagramatic notation for Wythoff constructions. The black and white plates in the book show solid models of three-dimensional polyhedra, and wire-frame models of projections of some higher-dimensional polytopes. At the end of each chapter Coxeter includes an "Historical remarks" section which provides an historical perspective of the development of the subject.
The contents of the third edition (1973) of Regular Polytopes
are as follows:
- Section I. Polygons and Polyhedra
- Section II. Regular and Quasi-Regular Solids
- Section III. Rotation Groups
- Section IV. Tessellations and Honeycombs
- Section V. The Kaleidoscope
- Section VI. Star Polyhedra
- Section VII. Ordinary Polytopes in Higher Space
- Section VIII. Truncation
- Section IX. Poincaré's Proof of Euler's Formula
- Section X. Forms, Vectors and Coordinates
- Section XI. The Generalised Kaleidoscope
- Section XII. The Generalised Petrie Polygon
- Section XIII. Section and Projections
- Section XIV. Star-Polytopes
Regular Polytopes is a standard reference work on regular polygons, polyhedra and their higher dimensional analogues. It is unusual in the breadth of its coverage; its combination of mathematical rigour with geometric insight; and the clarity of its diagrams and illustrations.