Curated OER
Forty Mental Math Angle Problems
In this angle worksheet, students answer forty mental math questions divided into four problem sets. These problems require students to remember angle facts and so simple calculations mentally.
Curated OER
Grouping Musical Instruments
Students study about musical instruments and group them into these categories: percussion, strings, woodwinds, and brass. After discussing these instruments, they independently complete the worksheet.
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.
Oswego City School District
Regents Exam Prep Center: Special Right Triangles 45, 45, 90
This Oswego City School District Regents Exam Prep tutorial shows two special formulas that are used to determined the measures of the legs of a 45-45-90 triangles. If you can't remember the formula, the tutorial gives you tips on other...
Purple Math
Purplemath: Special Angle Values: 30 60 90 and 45 45 90 Triangles
Explains a simple pictorial way to remember basic reference angle values. Provides other memory aids for the values of trigonometric ratios for these "special" angle values, based on 30-60-90 triangles and 45-45-90 triangles.
Math Open Reference
Math Open Reference: 45 45 90 Triangle
Explore the triangle inequality theorem with this helpful reference tool. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.
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.
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.
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.
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: 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.
Khan Academy
Khan Academy: Special Right Triangles
Use your knowledge of 30-60-90 and 45-45-90 triangles to solve some problems.
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."
Sophia Learning
Sophia: Two Special Triangles: Lesson 1
This lesson explains what 45-45-90 and 30-60-90 right triangles are and discusses their properties. It is 1 of 5 in the series titled "Two Special Triangles."
CK-12 Foundation
Ck 12: Trigonometry: Lengths of Sides in Isosceles Right Triangles
[Free Registration/Login may be required to access all resource tools.] Here you'll learn what an isosceles right triangle is, the relationships between the sides of an isosceles right triangle, and how to find the length of an unknown...
Windstream
Ojk's Precalculus Study Page: Evaluating and Graphing Sine and Cosine
An introduction to graphing the sine and cosine functions by using the 30-60-90 and 45-45-90 right triangle values of the two functions as guides.
Lawrence Hall of Science
The Math Page: Trigonometry: The Isosceles Right Triangle
Here is a site that clearly and thoroughly explains the trigonometry of a 45-45-90 right triangle. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site out to...
Geometry Help
Geometry Help: Right Triangles
Explains the basic concept of right triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
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.
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.
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...
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.
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?"...