Interactive Mathematics
Interactive Mathematics: Trigonometric Functions of Any Angle
Given a reference angle, you can find the trigonometric functions of any angle. The process is demonstrated in this lesson and examples are provided for practicing the concept.
Math Planet
Math Planet: Pre Algebra: Trigonometry
Learn about trigonometry by viewing examples and a video lesson.
Wolfram Research
Wolfram Math World: Half Angle Formulas
This page, from Eric Weisstein's comprehensive Math World site, offers information on half-angle formulas. The site includes traditional trigonometric fuctions half-angle formulas as well as hyperbolic half-angle formulas. Includes links...
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...
Wolfram Research
Wolfram Math World: Double Angle Formulas
Part of Eric Weisstein's comprehensive math site, this page deals with double-angle formulas. This site includes traditional trigonomic double-angle functions as well as hyperbolic trigonometric function. Includes links to related terms...
Mangahigh
Mangahigh: Shape: Use Trigonometry to Find Angles
Use trigonometry to determie the angle measures.
Wolfram Research
Wolfram Math World: Cut the Knot! Angles
Very good site with links to reviews of various angles.
Lawrence Hall of Science
The Math Page: Trigonometry: Analytic Trigonometry the Unit Circle
Here is a site that clearly and thoroughly explains the unit circle and all six trigonometric functions of all quadrantal angles. There are example problems solved, problems for the student to attempt, and answers to the student...
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.
Analyze Math
Analyze Math: Special Angles on Unit Circle
Learners explore the special angles between 0 and 2 pi on a unit circle. The special angles can be used to solve trigonometry problems.
Lawrence Hall of Science
The Math Page: Trigonometry: Radian Measure
Here is a site that clearly and thoroughly explains the radian measure of angles. There are example problems solved, problems for the student to attempt, and answers to the student problems.
Texas Instruments
Texas Instruments: Exploration of Trigonometry
Using TI Navigator, Cabri Jr and LearnCheck, students will explore how changing an angle in a triangle changes the ratio of the sides, and changing the sides can make changes an angle in a triangle. Students will then explore two...
Math Medics
S.o.s. Math: Double Angle and Half Angle Formulas
Double angles and half angles are explained through step by step examples. The steps are clear and easy to follow.
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.
Lawrence Hall of Science
The Math Page: Trigonometry: The Law of Sines
Work through an explanation of the law of sines, how it is used with an obtuse angle, and a proof of the law of sines. Great site for students studying trigonometry.
Analyze Math
Analyze Math: Special Triangles Used in Trigonometry
The trigonometry tutorial investigates special triangles. The activity includes isosceles right triangles and 30-60-90 triangles. The examples show how to obtain the six trigonometric ratios of the special angles using special triangles.
Lawrence Hall of Science
The Math Page: Trigonometry: The 30 60 90 Right Triangle
Here is a site that clearly and thoroughly explains the trigonometry of the 30-60-90 right triangle. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site out to...
Mangahigh
Mangahigh: Shape: 3 D Trigonometry
Test your knowledge of determing the lengths and angles of right triangles.
Mathigon
Mathigon: Geometry: Triangles and Trigonometry: Pythagoras' Theorem
Pythagoras' Theorem: In any right-angled triangle, the square of the length of the hypotenuse (the side that lies opposite the right angle) is equal to the sum of the squares of the other two sides. (A+B=C)
Khan Academy
Khan Academy: Adding and Decomposing Vectors Using Trigonometry
Use trigonometry to practice adding, decomposing, and finding vector angles from physics word problems.
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice: Right Triangles and Trigonometry
Practice using your graphing calculator for solving right triangle trigonometry and non-right triangle trigonometry. If you get stumped or if you would like to check your work, then select the View Solution button, which is located...
Lawrence Hall of Science
The Math Page: Trigonometry: Solve Right Triangles
Here is a site that clearly and thoroughly explains how to solve right triangles for any missing side or angle given any two pieces other sides or angles. There are example problems solved, problems for the student to attempt, and...
Mangahigh
Mangahigh: Shape: Use the Law of Sines for Finding Angles
Test your knowledge of using the law of sines to determine angle measures.
Lawrence Hall of Science
The Math Page: Trigonometry: Arc Length
Here is a site that clearly and thoroughly explains arc length and its relationship to radian measure of angles. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site...