CK-12 Foundation
Ck 12: Trigonometry: Sides of an Oblique Triangle
[Free Registration/Login may be required to access all resource tools.] This lesson covers using the Law of Cosines to find the third side of a triangle.
CK-12 Foundation
Ck 12: Trigonometry: Polar to Rectangular Conversions
[Free Registration/Login may be required to access all resource tools.] This lesson teaches you how to change Polar coordinates into rectangular coordinates.
That Quiz
That Quiz: Trigonometry
You can practice evaluating the six trigonometric functions and their inverse in radians or degrees. Four different levels are provided and it also tracks the number of correct answer.
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.
Purple Math
Purplemath: Sectors, Areas, and Arcs
Explains formulas for areas of sectors of circles and lengths of arcs. Demonstrates how to use the formulas in each of degrees and radians.
Other
Gobierno De Navarra: Trigonometria
Use these interactive activities as a supplementary material to visualize some basic concept of Trigonometry.
Calculator Soup
Calculator Soup: Trigonometric Functions Calculator
This online trigonometry calculator will calculate the sine, cosine, tangent, cotangent, secant and cosecant of angle values entered in degrees or radians. The trigonometric functions are also known as the circular functions.
Math Planet
Math Planet: Algebra 2: Angles
Features a definition, examples, and a video lesson all related to angles. [0:35]
CK-12 Foundation
Ck 12: Determination of Unknown Angles Using Law of Cosines
[Free Registration/Login may be required to access all resource tools.] This lesson covers using the Law of Cosines to find an angle in a triangle.