Legendre, A. M. (Adrien Marie), 1752-1833, Brewster, David, Sir, 1781-1868, Davies, Charles, 1798-1876 · New York, Wiley & Long · leaf 87
ere-fore DEF is also similar to ABC. BOOK IV. 87 PROrO:SlTION XXI. THEOREM. Tun triaiti^les, xchich have their homologous Mes parallel^ orperpcjidicular to each other^ are ai/nilar. Let 15AC, EDF, be two triangles. First, If the side AB is parallel to DE, andBC to EF, the angle ABC will be equal… … Secondly. If the side DE is perpen-dicular toAB, and the side DF to AC,the two angles I and II of- the quadri-lateral AIDII will be right angles ; andsince all the four angles are togetherequal to four right angles (Book 1. Prop. XXVI. Cor. 1.), the remaining two lAII, IDII, will be together equal…
Trigonometry · Geometry
Internet Archive · Wellesley College Library · Public Domain Mark 1.0. Free to use for anything.
