几何学是数学科学中历史最悠久,也是最成熟的一个分支.18世纪以前,欧几里得的欧氏几何一统天下,我们现在初中所学习的几何也属于欧氏几何的范畴.但到了19世纪,非欧几何的发现对几何学产生了深远的影响.本文从欧几里得的《几何原本》说起,与大家谈谈萨切里四边形与非欧几何的联系. Geometry is one of the oldest and most mature branches of mathematics, and before the eighteenth century the Euclidean geometry of Euclid was unified and the geometry we studied in the middle school now belongs to the category of Euclidean geometry. In the century, the discovery of non-Euclidean geometry has a far-reaching impact on geometry.This paper starts from the original “geometry” of Euclid and talks with you about the connection between the Sargent quadrangle and non-Euclidean geometry.