Excerpt from Plane and Solid Geometry In Geometry he is to study form, and he will find, for example, that two triangles must necessarily be equal if the three sides of the one are respectively equal to the three sides of the other. Before beginning the subject, however, there are certain terms which, although familiar, are used with such exactness as to require careful explanation. These terms are solid, sur face, line, angle (with various kinds Of each), and point. As with most elementary mathematical terms, such as number, space, etc., it is difficult to give them simple and satisfactory definition. Explanations can, however, be given which will lead the student to a reasonable understanding of them. 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.