Pierre Laurent Wantzel (5 June 1814 in Paris – 21 May 1848 in Paris) was a French mathematician who proved that several ancient geometric problems were impossible to solve using only compass and straightedge. In a paper from 1837, Wantzel proved that the problems of 1. * doubling the cube, and 2. * trisecting the angle are impossible to solve if one uses only compass and straightedge. In the same paper he also solved the problem of determining which regular polygons are constructible: — Adhémar Jean Claude Barré de Saint-Venant, on the occasion of Wantzel's death.