""An Elementary Treatise On The Application Of Trigonometry"" is a book written by John Farrar and published in 1840. The book is a comprehensive guide to the practical application of trigonometry, a branch of mathematics that deals with the relationships between the sides and angles of triangles. The book is aimed at students and teachers of mathematics, as well as engineers and surveyors who use trigonometry in their work.The book begins with an...