CK-12 Foundation
Ck 12: Interactive Geometry: 6.7 Applications of Similar Triangles
Learn how similar triangles have congruent corresponding angles and proportional corresponding sides.
CK-12 Foundation
Ck 12: Interactive Geometry: 7.8 Triangles in Applied Problems
Explore some problems you can solve with your knowledge of triangles and trigonometry.
PBS
Pbs Learning Media: Triangles: Targeted Math Instruction
Students will learn how to apply the properties and characteristics of all triangles to solve real-world problems and identify and use the unique characteristics of right, isosceles, equilateral, acute, obtuse, and scalene triangles.
Quia
Ixl Learning: The Pythagorean Theorem
Brush up on your math skills relating to the Pythagorean Theorem then try some practice problems to test your understanding.
Quia
Ixl Learning: Similar Triangles
Brush up on your math skills relating to similar triangles then try some practice problems to test your understanding.
Khan Academy
Khan Academy: Triangle Similarity Review
Review the triangle similarity criteria and use them to determine similar triangles.
Purple Math
Purplemath: The Pythagorean Theorem
Defines the Pythagorean Theorem, and demonstrates how to use this Theorem in connection with right-angled triangles.
Curated OER
45 45 90 and 30 60 90 Triangles
The formulas for 45-45-90 and 30-60-90 triangles and the use of the Pythagorean theorem to prove the formulas.
Ministry of Education and Employment of Spain
Red Escolar: Un Triangulo Sorprendente
In Spanish. Different activities which involve the following concepts: right triangles, perpendicular lines, classification of triangles, area of a square and Pythagorean theorem.
AAA Math
Aaa Math: Finding the Third Angle of a Triangle
Finding the third angle of a triangle becomes easier by the explanation and examples presented.
Pennsylvania State University
Pennsylvania State Univ.: Trilingual Packaging Dilemma
This site from the Pennsylvania State University provides a hands-on activity to bridge the gap between right triangles, 30-60-90 and 45-45-90 theorems, and trigonometry, and what every student wants to know, "When will I ever use this?"...
Other
Mathematics Internet Library: Free Internet Books
Practice problem worksheets are available for students needing to study basic terms relating to triangles and other math concepts.
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.
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.
ClassFlow
Class Flow: Difference of Squares (Algebra)
[Free Registration/Login Required] Pythagorean triples described using a number of triangles. Pythagorean Theorem reinforced using squares and triangles. Assessment built in.
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.
Shmoop University
Shmoop: Basic Geometry: Triangles
The geometry resource explores triangles. Descriptions, examples, and practice exercises are included.
Shmoop University
Shmoop: Basic Geometry: Pythagorean Theorem
Students learn about the Pythagorean Theorem. Notes, practice problems, and examples are included in the geometry resource.
Varsity Tutors
Varsity Tutors: Hotmath: Algebra Review: Types of Triangles
Find a quick, concise explanation of the different types of triangles. Examples are given and clearly explained.
Ducksters
Ducksters: Kids Math: Triangles
Learn about equilateral, right angle, and isosceles triangles on this site. Learn how they work, terms, tricks and examples. .
Calculator Soup
Calculator Soup: Pythagorean Theorem Calculator
This calculator solves the Pythagorean Theorem equation for sides a or b, or the hypotenuse c. The hypotenuse is the side of the triangle opposite the right angle.
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.