Khan Academy
Khan Academy: Right Triangle Word Problems
Solve word problems by modeling real-world (and not-so-real) situations as right triangles and using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Trigonometry: Special Triangle Ratios
[Free Registration/Login may be required to access all resource tools.] Use right triangle ratios to solve for sides of triangles.
Lawrence Hall of Science
The Math Page: Trigonometry: Trignometry of Right Triangles
Here is a site that clearly and thoroughly explains the trigonometry of a right triangle, including finding the values of all six trig functions given a single value. There are example problems solved, problems for the student to...
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.
Illustrative Mathematics
Illustrative Mathematics: G C, G Srt Setting Up Sprinklers
In this task, students must decide where to place sprinklers on a lawn so that the maximum area of the lawn will be watered. To solve it, they must find areas of sectors of circles and use trigonometric ratios to solve right triangles....
Khan Academy
Khan Academy: Solve for a Side in Right Triangles
Given one side length and an acute angle in a right triangle, find another side using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Trigonometry: Pythagorean Theorem for Solving Right Triangles
[Free Registration/Login may be required to access all resource tools.] This lesson applies the trigonometric ratios and their inverses to real-life situations.
Discovery Education
Discovery Education: Web Math: Calculate a Right Triangle
WebMath offers a java applet that allows you to input information about a right triangle, and then solves the triangle for any of the missing pieces of information. It also gives a detailed solution using the information that you provided.
Curated OER
Zona Land: Right Triangle Solver 1
A java applet that will solve a right triangle when you provide information for angle D and its opposite side d.
Purple Math
Purplemath: Right Triangle Word Problems
Demonstrates how to translate, set up, and solve basic right-triangle word problems.
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: Special Right Triangles
Use your knowledge of 30-60-90 and 45-45-90 triangles to solve some problems. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Purple Math
Purplemath: Basic Trigonometric Ratios: Examples
Demonstrates how to use trig ratios to do simple solving of triangles.
CK-12 Foundation
Ck 12: Geometry: Inverse Trigonometric Ratios
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to use inverse trigonometric ratios to solve for missing angles in right triangles.
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.
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.
CK-12 Foundation
Ck 12: Algebra: Solving Equations Using the Pythagorean Theorem
[Free Registration/Login may be required to access all resource tools.] Use the Pythagorean Theorem to find a right triangle's missing side lengths.
TeachEngineering
Teach Engineering: You've Got Triangles!
Students learn about trigonometry, geometry and measurements while participating in a hands-on interaction with LEGO MINDSTORMS NXT technology. First they review fundamental geometrical and trigonometric concepts. Then, they estimate the...
Khan Academy
Khan Academy: General Triangle Word Problems
Solve word problems that involve general triangles using trigonometry. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Intro to Inverse Trig Functions
Learn about arcsine, arccosine, and arctangent, and how they can be used to solve for a missing angle in right triangles.
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...
Texas Instruments
Texas Instruments: Real Life Real World Activity Forestry
Forest industry professionals make measurements in their work using tools including the Clinometer and the Biltmore Stick. These tools are based on the concepts of similar triangles and trigonometric ratios in a right triangle. This...
CK-12 Foundation
Ck 12: Geometry: Inverse Trigonometric Ratios
[Free Registration/Login may be required to access all resource tools.] Use the inverse trigonometric ratios.