Definitions for "Trigonometry"
That branch of mathematics which treats of the relations of the sides and angles of triangles, which the methods of deducing from certain given parts other required parts, and also of the general relations which exist between the trigonometrical functions of arcs or angles.
Study of triangles, the measurements of their parts and of angle functions and relations.
Study of the Relationships of Lines & Angles in the Triangle
Keywords:  treatise, science
A treatise in this science.