Non Euclidean Geometry , Coxeter pdf

No living geometer writes more clearly and beautifully about difficult topics than world famous professor H. S. M. Coxeter. When non-Euclidean geometry was first developed, it seemed little more than a curiosity with no relevance to the real world. Then to everyone’s amazement, it turned out to be essential to Einstein’s general theory of relativity! Coxeter’s book has remained out of print for too long.

,,,, Hats off to the MAA for making this classic available once more — Martin Gardner


Coxeter’s geometry books are a treasure that should not be lost. I am delighted to see “Non-Euclidean Geometry” back in print. — Doris Schattschneider



Throughout most of this book, non-Euclidean geometries in spaces of two or three dimensions are treated as specializations of real projective geometry in terms of a simple set of axioms concerning points, lines, planes, incidence, order and continuity, with no mention of the measurement of distances or angles. This synthetic development is followed by the introduction of homogeneous coordinates, beginning with Von Staudt’s idea of regarding points as entities that can be added or multiplied. Tranformations that preserve incidence are called collineations. They lead in a natural way to isometries or “congruent transformations.” Following a recommendation by Bertrand Russell, continuity is described in terms of order. Elliptic and hyperbolic geometries are derived from real projective geometry by specializing an elliptic or hyperbolic polarity which transforms points into lines (in two dimensions) or planes (in three dimensions) and vice versa.


An unusual feature of the book is its use of the general linear transformation of coordinates to derive the formulas of elliptic and hyperbolic trigonometry. The area of a triangle is related to the sum of its angles by means of an ingenious idea of Gauss.
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This treatment can be enjoyed by anyone who is familiar with algebra up to the elements of group theory. The present (sixth) edition clarifies some obscurities in the fifth, and includes a new section 15.9 on the author’s useful concept of inversive distance.


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thanks control+c anywho, here go book!

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heliiaruy yuraiile h


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