Solve missing triangle measures using the law of cosines. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Here is a site that clearly and thoroughly explains the law of cosines and how to use it. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site out to students who...

[Free Registration/Login may be required to access all resource tools.] Find an unknown angle of a side side side triangle using the Law of Cosines.

This page from MathWorld.com gives a good explanation of the Law of Cosines, which relates the lengths of the legs of a triangle to the angles. This site shows how the formula is derived, along with a triangle to clarify variables. Also...

This MathWorld page gives a good explanation of the Law of Sines, which relates the lengths of the sides of a triangle to the sines of the opposite angles. This site gives a picture to help clarify the variables used in the equation....

[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.

The online assessment demonstrates knowledge of Algebra II. The questions test students on the law of cosines.

[Free Registration/Login Required] This flipchart defines and uses the law of cosines to find the missing sides and angles of oblique triangles.

This is demonstration of how the law of sines works. It uses Java applets to manipulate the triangle and allows the user to explore what happens to the values of the triangle as the sides are changed.

An introduction to solving acute and obtuse triangles by using the law of cosines, including a derivation of the formula. Includes several pistures and examples.

[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.

Sixteen problems present practice working with the Law of Sines and Law of Cosines. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution"...

[Free Registration/Login may be required to access all resource tools.] Find the side of an oblique triangle using the Law of Cosines.

Defines and explores the law of cosines through examples and a video lesson. [1:41]

This MathWorld site gives a short discussion on acute triangles with links to related terms and topics. The site offers a discussion on the least number of acute triangles to compose various polygons, and a discussion on the relationship...

[Free Registration/Login may be required to access all resource tools.] A summary of when to use the law of cosines or the law of sines to solve triangles.

Here are four problems to solve using the Law of Cosines. Two are SSS problems; two are SAS problems. Two have detailed solutions; two have answers given only. Notice the link at the bottom that takes you to a Law of Cosines calculator -...

Your students are part of the Yellowstone National Park rescue team which has just been dispatched to help located a downed plane. How can they effectively use the Law of Sines and the Law of Cosines to assist them in finding the plane?...

BBC provides a three part lesson on solving triangles, by using the sine rule and cosine rule.

Based off of the hit television show NUMB3RS, this lesson has students discover the Pythagorean relationships of different triangle types. By the end of the lesson, students should be able to take three given side lengths and compute...

View examples of triangle identities, equations that are true for all triangles: Law of Sines, Law of Cosines, and Law of Tangents. Follow links to learn more about the purpose and examples of each identity.

Concepts in Trigonometry are explained and illustrated here by a member of the math department at Borough of Manhattan Community College.

These two navigation problems employ the use of the law of sines or cosines and basic trigonometry. Each problems includes links to a sketch of the problem for visual help, and to a solution.

Great application of trig and introduction to the trig functions. Also found here are the Law of Sines and Law of Cosines as well as other trig topics to review.