H S M Coxeter: 3 books

Polytopes are geometrical figures bounded by portions of lines, planes, or hyperplanes. In plane (two dimensional) geometry, they are known as polygons and comprise such figures as triangles, squares, pentagons, etc. In solid (three dimensional) geometry they are known as polyhedra and include such...

For over eighty years this delightful classic has provided entertainment through mathematical problems commonly known as recreations. Although they often involve fundamental mathematical methods and notions, their chief appeal is as games or puzzles rather than the usefulness of their conclusions. This...

The name non-Euclidean was used by Gauss to describe a system of geometry which differs from Euclid's in its properties of parallelism. Such a system was developed independently by Bolyai in Hungary and Lobatschewsky in Russia, about 120 years ago. Another system, differing more radically from Euclid's,...