# Dissection of Gerwien's Triangle into a Saccheri Quadrilateral on the Sphere

Dissection of Gerwien's Triangle into a Saccheri Quadrilateral on the Sphere

This Demonstration shows Gerwien's dissection of a spherical triangle into a spherical Saccheri quadrilateral. Two cases are treated, namely that from Figures 1 and 3 from Gerwien's 1833 article [1].