Trigonometry: An Overview of Important Topics

A short, friendly introduction that starts with right triangles and solving triangles, then moves on to graphs, identities, equations and the laws of sines and cosines. Ideal for a first course or a quick refresher.

Richard W. Beveridge

A classic school textbook that introduces trigonometry step by step, from measuring angles to ratios, identities, logarithms and solving triangles. Its many worked examples and exercises make it a great first book.

J. B. Lock

A practical guide to right triangle trigonometry, covering Pythagoras' theorem, sine, cosine and tangent, angles of elevation and depression, and bearings. Real-world problems with answers help you build confidence fast.

Southern Cross University

Compact course notes that cover radian measure, the six trigonometric ratios, exact values, key identities, inverse functions and trigonometric equations. They end with tutorial exercises for engineering and science students.

Glasgow Caledonian University

A brief introduction to the basics: degrees and radians, the unit circle, the six trigonometric functions and the double-angle formula. A quick read to review the essentials before a calculus course.

P. Maidorn