This book presents plane geometry following Hilbert's axiomatic system. It is inspired on R. Hartshome's fantastic book Geometry: Euclid and Beyond, and can be considered as a careful exposition of most of chapter II of that book. It must be remarked that non-euclidean geometries, i.e. geometries not satisfying the fifth postulate of Euclid, enter the scene, in a natural way, from the very beginning. The vast majority of plane geometry texts are only concerned with euclidean...
