Excerpt from The Elements of Railroad Engineering, Vol. 2: Prepared for Students of the International Correspondence Schools, Scranton, Pa
1180. If two triangles have two sides and the included angle of the one equal to two sides and the included angle of the other, the triangles are equal in all their parts. Thus, in the two triangles A B C and D E F, Fig. 236, if the side A B is equal to the side D E; the side B C to the side E F, and the angle B to the angle E, the triangles are equal in every respect.
1181. If a straight line, A B, Fig. 237, intersects two parallel straight lines, C D and E F it is called a secant A with respect to them, and the eight angles formed about the points of intersection have different names applied to them with respect to each other, as follows:
First - Interior angles on the same side are those which lie on the same side of the secant and within the other two lines. Thus, in Fig. 237, H G D and G H F are interior angles on the same side.
Second Exterior - angles on the same side are those which lie on the same side of the secant but without the other two lines. Thus, A G D and F H B are exterior angles on the same side.
Third Alternate - interior angles are those which lie on opposite sides of the secant and within the other two lines. Thus, C G H and G H F are alternate interior angles.
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. Это и многое другое вы найдете в книге The Elements of Railroad Engineering, Vol. 2 (International Correspondence Schools)