Curated OER
Trigonometry Realms
Excellent site reviewing the realms of Trigonometry. Topics Include the trig functions, graphs, right triangles and much more.
Northeast Parallel Architectures Center, Syracuse University
Npac Reu Program: Trigonometry Review
The Northeast Parallel Architectures Center, Syracuse University, provides a review and tutorial site on trigonometry. The information is in-depth and can be accessed by clicking on the various links in the outline.
University of Colorado
University of Colorado: Ph Et Interactive Simulations: Trig Tour
Take a tour of trigonometry using degrees or radians! Look for patterns in the values and on the graph when you change the value of theta. Compare the graphs of sine, cosine, and tangent.
Other
Trigonometry: A Crash Review
This site really is a crash review on trigonometry! Formulas, functions - you name it, it's covered! Also includes self quizzes for practice.
TeachEngineering
Teach Engineering: You've Got Triangles!
Students learn about trigonometry, geometry and measurements while participating in a hands-on interaction with LEGO MINDSTORMS NXT technology. First they review fundamental geometrical and trigonometric concepts. Then, they estimate the...
Wolfram Research
Wolfram Math World: Cut the Knot! Angles
Very good site with links to reviews of various angles.
National Council of Teachers of Mathematics
The Math Forum: High School Archive for Trigonometry
This site from the Math Forum with Dr. Math is an excellent site with answers to submitted questions on trigonometry. In addition the student can submit their own questions. Links are provided for additional information.
University of Saskatchewan (Canada)
Exercises in Math Readiness for University Study: Trig
Read a lesson, look at examples, and try easy, medium, and advanced problems from a variety of trigonometry topics: radian measure of angles, trigonometric functions, trigonometric identities, and modeling with trigonometric functions.
Other
Math Mistakes: Common Trigonometry Mistakes
Learn from other student's mistakes by reviewing examples of the following Trigonometry topics: values of trigonometric functions, values of inverse trigonometric functions, solving triangles, simplifying trigonometric expressions, and...
Other
North Carolina Su: Triangles, Circles, and Waves (Oh My!)
This site has a basic overview of trigonometry focusing on the trig functions, trig ratios, and the unit circle.
Other
Brown Math: A 10 Minute Trig Review
Looking for a 10-minute review of the major concepts of trigonometry? This site is a quick recap of degrees and radians, SOH CAH TOA, Pythagorean identities, and special right triangles are all found here.
Other
Dans Math: Lessons: Trigonometry
College professor Dan Bach reviews basic trig concepts, including trig functions, right triangles, circles, radians, and polar coordinates. Site includes animated graphs and detailed examples.
Paul Dawkins
Paul's Online Notes: Algebra & Trig Review
The tutorial reviews algebra and trigonometric topics needed in Calculus. Topics examined are solving equations, rational expressions, absolute value, solving trigonometric functions, exponentials, and logarithms. Class notes,...
Lawrence Hall of Science
The Math Page: Trigonometry: Trig Functions of an Acute Angle
Here is a site that clearly and thoroughly explains the trigonometric functions of acute angles within a right triangle. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point...
Purple Math
Purplemath: Converting Between Radians and Degrees
Describes degrees and radians with respect to angles, the reason for the invention and use of radians, and how to convert between radians and degrees.
Purple Math
Purplemath: Proving Trigonometric Identities
An "identity" is a tautology, an equation or statement that is always true, no matter what. Proving an identity is very different in concept from solving an equation. This resource demonstrates some useful techniques for proving...
Purple Math
Purplemath: Special Angle Values: 30 60 90 and 45 45 90 Triangles
Explains a simple pictorial way to remember basic reference angle values. Provides other memory aids for the values of trigonometric ratios for these "special" angle values, based on 30-60-90 triangles and 45-45-90 triangles.
Other
University of Cambridge: Spherical Trigonometry
Very good site that acts as a tutorial/review site on Spherical Trigonometry. Many diagrams and formulas are included.
Khan Academy
Khan Academy: Right Triangle Trigonometry Review
Review right triangle trigonometry and how to use it to solve problems.
Purple Math
Purplemath: Inverses of Trigonometric Ratios
You know that you can take side lengths and find trig ratios, and you know you can find trig ratios (in your calculator) for angles. What is missing is a way to go from the ratios back to the original angles. And that is what "inverse...
Math2
Math2.org: Trigonometry Tables
Three trig tables are provided for student and teacher reference. The first table lists the sine, cosine, tangent, secant, cosecant, and cotangent values of all whole-number angles from 0 to 90. The radian equivalent (to four decimals)...
Wolfram Research
Wolfram Math World: Trigonometric Functions
This site from MathWorld.com is a site full of links to very extensive documentation on the trigonometric functions.
![Paul's Online Notes: Trig Cheat Sheet [Pdf] Unknown Type](https://d15y2dacu3jp90.cloudfront.net/images/attachment_defaults/resource/large/FPO-knovation.png "Paul's Online Notes: Trig Cheat Sheet [Pdf] Unknown Type")
Paul Dawkins
Paul's Online Notes: Trig Cheat Sheet [Pdf]
A trigonometry "cheat sheet" to use as a reference when completing trigonometry homework. Lists basic facts, properties, identities, formulas, and inverse trigonometric functions.
Other
Trigonometry: A Quick Review
This site is a personal site from David Eisenberg and it contains brief but great review information for trigonometry. This particular site focuses on sine and cosine inlcuding a small circle graph. Clicking on the index link provides...