Excerpt from An Elementary Treatise on Plane Spherical Trigonometry 1. Trigonometry is the science which treats of angles and triangles. 2. Plane Trigonometry treats of plane triangles. [B. p. 36.] 3. To solve a Triangle is to calculate certain of its sides and angles when the others are known. It has been proved in Geometry that, when three of the six parts of a triangle are given, the triangle can be constructed, provided one at least of the given parts is a side. In these cases, then, the unknown parts of the triangle can be determined geometrically, and it may readily be inferred that they can also be determined algebraically. But a great difficulty is met with on the very threshold of the attempt to apply the calculus to triangles. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.