Projective Geometry

Abstract

The geometry we did at school (or maybe didn’t) was mostly very dull. It was all about lengths and angles; proofs were often about showing that certain angles or lengths were equal. However, there is much geometry in which the lengths of lines and sizes of angles are not considered at all. This so-called projective geometry was heavily studied in the nineteenth century but became unfashionable. This was perhaps because it seemed to have no practical value and did not provide a foundation for other things. Nevertheless, it has a certain elegance and beauty.