Introduction to Non-Euclidean Geometry

This book has been written in an attempt to provide a satisfactory textbook to be used as a basis for elementary courses in Non-Euclidean Geometry. The need for such a volume, definitely intended for classroom use and containing substantial lists of exercises, has been evident for some time. It is hoped that this one will meet the requirements of those instructors who have been teaching the subject regularly, and also that its appearance will encourage others to institute such courses. The benef...