Wolfram Research
Wolfram Math World: 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...
Texas Instruments
Texas Instruments: Sin, Cos, and Tan of Right Triangles
In this activity, students explore a right angled triangle and its trigonometric concepts. They investigate the trigonometric ratios for the angles of the triangle.
Texas Instruments
Texas Instruments: What's the Trig?
Students will be introduced to right triangle trigonometry. They will use the TI-89 and Geometer's Sketchpad to construct a right triangle and calculate sin, cosine, and tangent of various acute angles.
Texas Instruments
Texas Instruments: Discover Law of Sines
Using Cabri Jr students will be able to visualize the umbiguous case as well as when one cannot create a triangle.
Analyze Math
Analyze Math: Sine Law Problems
Here are six problems to solve using the Law of Sines. One of the problems addresses the ambiguous case. Four have detailed solutions; two have answers given only. Notice the link at the bottom that takes you to a Law of Sines calculator...
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Introduccion a La Trigonometria
This is an interactive activity introducing the concept of trigonometry and working with trigonometric functions to solve right triangles.
Other
Trig Without Tears: Solving Triangles
This page provides a good explanation of how to solve oblique triangles (triangles containing no right angles.) The Law of Cosines section is about halfway of the way down the page.
Other
Brown Math: A 10 Minute Trig Review
Looking for a 10-minute review of the major concepts of trigonometry? This site is a quick recap of degrees and radians, SOH CAH TOA, Pythagorean identities, and special right triangles are all found here.
Other
Karl's Calculus Tutor: Trigonometric Functions
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.
Math Planet
Math Planet: Algebra 2: Sines
Defines and examines the law of sines through examples and a video lesson. [2:02]
Math Planet
Math Planet: Algebra 2: Cosines
Defines and explores the law of cosines through examples and a video lesson. [1:41]
McGraw Hill
Glencoe Mathematics: Quiz on Trigonometric Ratios in Right Triangles
The online assessment demonstrates knowledge of advanced mathematical concepts in Algebra II. The questions test students on trigonometric ratios in right triangles.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Quiz on Solving Right Triangles
Learners demonstrate comprehension of advanced mathematical concepts in Trigonometry. The questions check understanding on the topic of solving right triangles.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Self Check Quiz on the Law of Sines
The online assessment demonstrates knowledge of Algebra II. The questions test students on the law of sines.
McGraw Hill
Glencoe Mathematics: Quiz on the Ambiguous Case for the Law of Sines
The online assessment demonstrates knowledge of Algebra II. The questions test students on the ambiguous case for the law of sines.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Self Check Quiz on Law of Cosines
The online assessment demonstrates knowledge of Algebra II. The questions test students on the law of cosines.
Mangahigh
Mangahigh: Shape: Use the Law of Sines for Finding Lengths
Deterime how to use the law of sines for finding lengths.
Mangahigh
Mangahigh: Shape: Use the Law of Sines for Finding Angles
Test your knowledge of using the law of sines to determine angle measures.
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...
Math Is Fun
Math Is Fun: Triangle Identities
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.
Math Is Fun
Math Is Fun: Trigonometric Identities
A good introduction to trigonometric identities, equations that are always true for a right triangle and require knowledge of the functions sine, cosine, and tangent.
Math Is Fun
Math Is Fun: Solving Triangles
Find guidelines to help you "solve" triangles, which means finding the value of missing sides and angles. Provided are examples of six scenarios in which you can solve a triangle's missing measurements, as well as relevant equations,...
Khan Academy
Khan Academy: Solve Triangles Using the Law of Sines
Solve missing triangle measures using the law of sines. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Solve Triangles Using the Law of Cosines
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.