By H.S.M. Coxeter
In Euclidean geometry, buildings are made with ruler and compass. Projective geometry is less complicated: its structures require just a ruler. In projective geometry one by no means measures something, as an alternative, one relates one set of issues to a different by way of a projectivity. the 1st chapters of this publication introduce the $64000 strategies of the topic and supply the logical foundations. The 3rd and fourth chapters introduce the recognized theorems of Desargues and Pappus. Chapters five and six utilize projectivities on a line and aircraft, respectively. the subsequent 3 chapters boost a self-contained account of von Staudt's method of the idea of conics. the fashionable strategy utilized in that improvement is exploited in bankruptcy 10, which bargains with the best finite geometry that's wealthy adequate to demonstrate the entire theorems nontrivially. The concluding chapters express the connections between projective, Euclidean, and analytic geometry.