EngageNY
From Circle-ometry to Trigonometry
Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.
Del Mar College
Formulas for Elementary and Intermediate Algebra
Give your scholars the support they need to work with formulas. A reference page offers definitions and picture examples of perimeter, area, surface area, volume, the Pythagorean theorem, a variety of shapes, and more.
EngageNY
Sine and Cosine of Complementary Angles and Special Angles
Building trigonometric basics here will last a mathematical lifetime. Learners expand on the previous lesson in a 36-part series by examining relationships between the sine and cosine of complementary angles. They also review the...
EngageNY
Prove the Pythagorean Theorem Using Similarity
Amaze your classes with the ability to find side lengths of triangles immediately — they'll all want to know your trick! Learners use the Pythagorean Theorem and special right triangle relationships to find missing side lengths.
Curated OER
Practice: Word Problems
Congratulations, you've just hit the word problem jackpot! Covering an incredible range of topics from integers and fractions, to percents, geometry, and much more, this collection of worksheets will keep young mathematicians...
Curated OER
Special Right Triangles Homework
In this geometry worksheet, students solve both kinds of special right triangles. There are 12 questions with multiple parts.
Wolfram Research
Wolfram Math World: Pythagorean Triple
This site provides extensive information about Pythagorean triples. It begins by explaining its relation to the Pythagorean theorem, and then gives ways to generate Pythagorean triples using relatively prime numbers and Fibonacci numbers.
Analyze Math
Analyze Math: Special Triangles Used in Trigonometry
The trigonometry tutorial investigates special triangles. The activity includes isosceles right triangles and 30-60-90 triangles. The examples show how to obtain the six trigonometric ratios of the special angles using special triangles.
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.
Mangahigh
Mangahigh: Shape: 3 D Trigonometry
Test your knowledge of determing the lengths and angles of right triangles.
CK-12 Foundation
Ck 12: Geometry: Recognize 45 45 90 Right Triangles
[Free Registration/Login may be required to access all resource tools.] Recognize special right triangles and their properties.
CK-12 Foundation
Ck 12: Geometry: 45 45 90 Right Triangles
[Free Registration/Login may be required to access all resource tools.] Apply the special properties of 45-45-90 right triangles.
McGraw Hill
Glencoe Mathematics: Online Study Tools: Special Right Triangles
This site gives a short interactive quiz which allows students to self-assess their understanding of the concept of special right triangles.
CK-12 Foundation
Ck 12: 45 45 90 Triangles
[Free Registration/Login Required] Students use a baseball field to determine the distance between points and 45-45-90 triangles. Click learn more to watch a video and click challenge me to answer a practice question.
Illustrative Mathematics
Illustrative Mathematics: F Tf Special Triangles 1
Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.
Illustrative Mathematics
Illustrative Mathematics: F Tf Special Triangles 2
Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.
Illustrative Mathematics
Illustrative Mathematics: F Tf Equilateral Triangles and Trigonometric Functions
The purpose of this task is to apply knowledge about triangles to calculate the sine and cosine of 30 and 60 degrees. Aligns with HSF-TF.A.3.
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.
CK-12 Foundation
Ck 12: Geometry: Special Right Triangles Study Guide
[Free Registration/Login may be required to access all resource tools.] Different types of right triangles and trigonometric ratios for special right triangles are covered in this study guide.
CK-12 Foundation
Ck 12: Geometry: 30 60 90 Right Triangles Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept teaches students about the 30-60-90 special right triangle and how to apply its properties.
CK-12 Foundation
Ck 12: Geometry: 45 45 90 Right Triangles Intermediate
[Free Registration/Login may be required to access all resource tools.] This concept teaches students about the 45-45-90 special right triangle and how to apply its properties.
Khan Academy
Khan Academy: Special Right Triangles
Use your knowledge of 30-60-90 and 45-45-90 triangles to solve some problems.
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.
Sophia Learning
Sophia: Two Special Triangles: Lesson 5
This lesson explains what 45-45-90 and 30-60-90 right triangles are and discusses their properties. It is 5 of 5 in the series titled "Two Special Triangles."