The Elements Of Non-Euclidean Plane Geometry And Trigonometry - Illustrated

An Unabridged Printing, To Include Over 100 Figures - Chapters: The Parallel Postulate, And The Work Of Saccheri, Legendre, And Gauss - The Work Of Bolyai, Lobatschewsky, And Riemann, The Founders Of Non-Euclidean Geometries - The Hyperbolic Plane Geometry - The Hyperbolic Plane Trigonometry - Measurements Of Length And Area, With The Aid Of The Infinitesimal Calculus - The Elliptic Geometry - The Elliptic Plane Trigonometry - The Consistency Of The Non-Euclidian Geometries And The Impossibility Of Proving The Parallel Postulate - Index Of Authors - Comprehensive Subject Index