First published in 1781, this book provides a comprehensive introduction to trigonometry. It includes detailed explanations of the properties and relations of sines, tangents, and other trigonometric functions, as well as their applications in various fields. With its clear and concise explanations, this book is an essential resource for anyone studying or teaching trigonometry.This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it.This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.