[Free Registration/Login may be required to access all resource tools.] Find all angles on the unit circle matching exact trig ratios. Resource includes examples, videos, and practice problems.

Students find and calculate the angle that light is transmitted through a holographic diffraction grating using trigonometry. After finding this angle, student teams design and build their own spectrographs, researching and designing a...

[Free Registration/Login may be required to access all resource tools.] This concept teaches students to find the sine, cosine, and tangent of right triangles.

[Free Registration/Login may be required to access all resource tools.] Find the sine, cosine, and tangent of right triangles.

This list of trigonometric identities includes the factoring formulas near the bottom. A great tool for reference.

In Spanish. Interactive activities online on various geometric and trigonometric concepts such as area, perimeter, secants, tangents, etc. A terrific resource for students. Site is organized acoording to shape. (triangle, quadrilaterals,...

A collection of lessons, practice activities, and a teacher resource that will aid your exploration and understanding of special right triangles.

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.

Given one side length and an acute angle in a right triangle, find another side using trigonometry.

Get information about trigonometric functions by viewing examples and a video lesson. [2:08]

Defines and examines the law of sines through examples and a video lesson. [2:02]

An example and a video lesson help to explain inverse functions. [0:38]

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...

This site gives a definition for what a trigonometric equation is, gives a listing of the simplest trigonometric equations, and lists seven main methods of solution of trigonometric equations with examples.

This MathWords.com site lists the equations for all of the trigonometric identities.

Some trigonometric equations can be solved only numerically. But a great many can be solved in closed form and simple procedures. This web page shows you how to do it in five steps (or fewer)!

Defines the Pythagorean Theorem, and demonstrates how to use this Theorem in connection with right-angled triangles.

Explains formulas for areas of sectors of circles and lengths of arcs. Demonstrates how to use the formulas in each of degrees and radians.

This lesson will illustrate how to use a calculator to find the value of a trigonometric value. It is 2 of 5 in the series titled "Trigonometric Values from a Calculator."

This lesson will illustrate how to use a calculator to find the value of a trigonometric value. It is 5 of 5 in the series titled "Trigonometric Values from a Calculator."

The definitions of the six trig ratios are presented here, along with several examples of how to determine the ratios given 2 or more sides of a right triangle.