Interactive Mathematics
Interactive Mathematics: Trigonometric Functions
Just about everything you need to know about trigonometry can be found here. Interactive examples and demonstrations help to enhance the lessons. Although not required, the tutorial uses Live Math and Scientific Notebook.
University of Vienna (Austria)
Univ of Vienna: Trigonometric Functions
An interactive tool to discover how the trig functions came to be. Applets are used in this interactive learning tool. Examples exercises are also given.
Oswego City School District
Regents Exam Prep Center: Law of Sines and Law of Cosines
This tutorial examines the law of sines and the law of cosines. Includes class notes, examples, and a variety of practice problems with solutions. The teacher resource consists of a lab that utilizes the law of sines and the law of cosines.
Khan Academy
Khan Academy: Angular Measure 2
Looking for an easier way to do angular measurements? This page introduces you to a trick by using skinny triangles with small angles. The skinny triangles lets the astronomer assume right triangles and then they can use trigonometry to...
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...
CK-12 Foundation
Ck 12: Geometry: Inverse Trigonometric Ratios
[Free Registration/Login may be required to access all resource tools.] Use the inverse trigonometric ratios.
Wolfram Research
Wolfram Math World: Cut the Knot! Angles
Very good site with links to reviews of various angles.
Math Planet
Math Planet: Geometry: Mean and Geometry
The geometric mean is explained through examples and a video lesson. [1:12]