""Elements of Geometry and Trigonometry"" is a comprehensive textbook written by Adrien-Marie Legendre, a French mathematician and surveyor. The book covers the principles of geometry and trigonometry, including Euclidean geometry, plane and spherical trigonometry, and applications of these principles in various fields such as astronomy, surveying, and navigation. The text is divided into three parts, with the first part covering the basics of Euclidean geometry, including points, lines, angles, and circles. The second part delves into plane and spherical trigonometry, covering topics such as trigonometric functions, identities, and applications in solving triangles. The third part of the book discusses the practical applications of geometry and trigonometry, including their use in surveying, navigation, and astronomy. The book is written in a clear and concise style, making it accessible to students and professionals alike. It is a valuable resource for anyone seeking to deepen their understanding of these fundamental mathematical concepts.This scarce antiquarian book is a facsimile reprint of the old original and may contain some imperfections such as library marks and notations. Because we believe this work is culturally important, we have made it available as part of our commitment for protecting, preserving, and promoting the world's literature in affordable, high quality, modern editions, that are true to their original work.