Sophia Learning
Sophia: Using Right Triangle Trigonometry to Find the Area of Regular Polygons
This lesson will demonstrate how to use right triangle trigonometry and special right triangles (45-45-90 and 30-60-90) to find the area of triangles given the side lengths of the polygon. It is 2 of 4 in the series titled "Using Right...
Sophia Learning
Sophia: Using Right Triangle Trigonometry to Find the Area of Regular Polygons
This lesson will demonstrate how to use right triangle trigonometry and special right triangles (45-45-90 and 30-60-90) to find the area of triangles given the side lengths of the polygon. It is 4 of 4 in the series titled "Using Right...
ClassFlow
Class Flow: Right Triangles
[Free Registration/Login Required] Use this flipchart to help your high school students understand right triangles using the Pythagorean Theorem.
ClassFlow
Class Flow: Trigonometry
[Free Registration/Login Required] Students explore trigonometric functions using the interactive features of Activstudio. Students apply their understanding of trigonometric sense to determine the side lengths and angles of various...
Fun Trivia
Fun Trivia: Right Triangles Trivia Quiz
Take this ten question quiz on right triangles as a review for a quiz or test. After submitting your results, you will get step by step instructions for each problem.
Doina Popovici
Math Play: Pythagorean Theorem Game
Find the unknown side in the right triangle using the Pythagorean theorem in this online game.
ClassFlow
Class Flow: Angle This Way
[Free Registration/Login Required] Students will identify right, acute and obtuse triangles using many interactive tools available in ACTIVstudio 3.0. Students will be engaged using a magnifier tool, the fill tool, and drag and drop and...
ClassFlow
Class Flow: Basic Right Triangle Trigonometry
[Free Registration/Login Required] This flipchart shows the basic relationships between trig functions and the sides and angles of a right triangle.
ClassFlow
Class Flow: Braun Right Triangles
[Free Registration/Login Required] This lesson is an exploration of variations of right triangles. Use as a warm up on square roots introduced in this flipchart. [Requires Adobe Reader.]
ClassFlow
Class Flow: Understanding Basic Triangles
[Free Registration/Login Required] This lesson presents an introduction to triangles and the methods of identifying them. It includes opportunities for students to interactively identify triangles. It also includes: assessment questions...
Math Is Fun
Math Is Fun: Right Angled Triangles
The resource investigates right triangle. Topics explored are isosceles, scalene, and 3,4,5 triangles. Examples, illustrations, and definitions are included.
Interactive Mathematics
Interactive Mathematics: The Right Triangle and Applications
Learn how to "solve" a right triangle and apply the concept to real world situations using angles of elevation and depression.
University of Saskatchewan (Canada)
University of Saskatchewan: Triangles
This site from the University of Saskatchewan provides an explanation of similar triangles, the Pythagorean theorem, and the distance between arbitrary points in a plane. Example problems for each of these concepts are provided.
University of British Columbia
University of British Columbia: Proof of the Pythagorean Theorem
A geometric model that proves the Pythagorean Theorem in a step-by-step diagram that students can advance at their own pace. Requires Java.
McGraw Hill
Glencoe: Self Check Quizzes 2: The Pythagorean Theorem
Test your knowledge of the Pythagorean Theorem with these practice problems. Each question has a "Hint" link to help. At the bottom of the page click the "Check It" button and the correct answer for each problem appears beside it. Also,...
Walter Fendt
Walter Fendt: Thales' Circle
A short interactive activity to prove that a triangle inscribed in a semicircle is right-angled.
Rice University
Rice University: Cynthia Lanius: Hidden Polygon Activity
On this site students are instructed to locate different types of polygons on triangle grid paper. This page can be printed so that students can actually draw them. It also gives a definitions link for each polygon.
Math Open Reference
Math Open Reference: Cotangent
Learn about cotangents with this helpful reference tool. Provides a detailed definition and examples that enhance further explanation. Includes links to related topics.
Calculator Soup
Calculator Soup: Right Triangles Calculator
Use this calculator to find the unknown angles in a right triangle using the Pythagorean Theorem. Once you know the sides you can calculate the perimeter, semiperimeter, area, and the altitudes.