Excerpt from The Elements of Euclid, Viz; The First Six Books: Together With the Eleventh and Twelfth; The Errors, by Which Theon, or Others, Have Long Ago Vitiated These Books, Are Corrected, and Some of Euclid's Demonstrations Are Restored; Also, the Book of Euclid's Data, in Like Manner Corrected In this edition, Ptolemy's Proposition concerning a property of quadrilateral figures in a circle, is added at the end of the sixth Book. Also the Note on the 29th Proposition, Book 1st, is altered, and made more ex plicit, and a more general Demonstration is given, in stead of that which was in the Note on the l0th Defi nition of Book 11th; besides, the Translation is much amended by the friendly assistance of a learned gen tleman. 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.