Plane Trigonometry Mensuration And Spherical Trigonometry Classic Reprint PDF Download

Excerpt from Plane Trigonometry, Mensuration, and Spherical Trigonometry If we have a line of any length, we can represent it numerically by the number of times it contains a given line, which we take to represent unity. Thus if we take a line a foot long to be the unit of length, a line seven feet long can be represented by 7. Of course, the same holds good of any other line. And so when we speak of a line 8, 5, or whatever the number may be, we mean that the line in question contains 8 or 5 of the given unit, as 8 feet, or 5 feet. And of course, if we can represent lines by num bers, we can generalize the numbers by letters, and thus we can represent lines by algebraical symbols; so that a b c, a: g z, &c. May be understood to represent lines. In the same manner as before, if we speak of a line a, we mean a line containing as many units of length (e.g. Feet) as a contains units of number. On the same principle we may express angles by numbers or by letters. This is done by dividing the right angle into 90 equal parts, each of which is called a degree, and dividing the degree into 60 equal parts, each called a minute, and the minute into 60 equal parts, each called a second. An angle is then expressed as being so many degrees, with odd minutes and seconds, e. G. 36 degrees, 57 minutes, 31 seconds, (which is usually written 36 57' 31 in the same manner as a line is expressed by so many yards, with odd feet and inches. Of course, as we can thus represent angles by numbers, we may also represent them by letters, and may have angles a, b, c; where the angle A (for instance) means that the angle contains as many degrees and parts of a degree as A contains units and parts of a unit.' 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.