Astronomy

ISBN: 9781440039461 出版年：2016 页码：167 R Ball Forgotten Books

I. The Measurement of Angles — We assume that the pupil, before he begins to learn astronomy, knows at least as much geometry as is contained in the first three books of Euclid. It will also be greatly to his advantage to have some acquaintance with trigonometry but this will not be indispensable for the reading of this volume, which is only an intro duction to the science.