Lawrence Hall of Science
The Math Page: Skill in Algebra: The Pythagorean Theorem
Here is a site that clearly and thoroughly explains the Pythagorean Theorem from solving for missing sides of a right triangle through its proof. There are example problems solved, problems for the student to attempt, and answers to the...
OER Commons
Oer Commons: Pre Assessment
Students solve for missing angle measures by applying what they have learned about types of angles and the angle measures of polygons. Students do a pre-assessment at the end of the lesson.
Curated OER
Webmath: Find Out Things About a Right Triangle
Gives basic info about a right triangle. Also students can substitute values for sides or angles in order to find missing values. The method for solving is then explained.
Illustrative Mathematics
Illustrative Mathematics: G Gpe.5 Triangles Inscribed in Circle
In this task, students use ideas about linear functions to determine when certain angles are right angles. They use the fact that two lines (if not vertical or horizontal) are perpendicular when their slopes are inverse reciprocals, as...
Maths Challenge
Maths challenge.net: Right Time
You will need to do some visualizing to solve this "Right Time" problem. Have fun!
University of Cambridge
University of Cambridge: Nrich: Tessellating Triangles
The challenge at this one page website, involves tessellation and triangle. Should you accept this challenge, you will find helpful teacher notes and the solution available right at the website.
Geometry Help
Geometry Help: Pythagorean Theorem
Explains the basic concept of the Pythagorean Theorem with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Cuemath
Cuemath: Pythagoras Theorem
In this lesson, you will learn about the Pythagoras theorem, its derivations, and equations followed by solved real-world problems on the Pythagoras theorem triangle and squares.
Curated OER
Zona Land: Trigonometry Right Triangles
Introduction to right triangles and how to solve them using trigonometric functions. Very nice interactive demonstration of what happens when the angle measurements change and how it effects the calculations. This visual might be just...
Curated OER
Zona Land: Trigonometry Right Triangles
Introduction to right triangles and how to solve them using trigonometric functions. Very nice interactive demonstration of what happens when the angle measurements change and how it effects the calculations. This visual might be just...
Curated OER
Zona Land: Trigonometry Right Triangles
Introduction to right triangles and how to solve them using trigonometric functions. Very nice interactive demonstration of what happens when the angle measurements change and how it effects the calculations. This visual might be just...
Curated OER
Zona Land: Trigonometry Right Triangles
Introduction to right triangles and how to solve them using trigonometric functions. Very nice interactive demonstration of what happens when the angle measurements change and how it effects the calculations. This visual might be just...
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.
Texas Instruments
Texas Instruments: Real Life Real World Activity Carpentry
Carpenters use applications of geometry in their work, including the properties of right triangles and circles. This activity uses Cabri Jr. Geometry software to make measurements and solve problems based on carpentry situations....
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...
CK-12 Foundation
Ck 12: Geometry: Laws of Sines and Cosines
[Free Registration/Login may be required to access all resource tools.] This concept teaches students to find missing sides and angles in non-right triangles using the Laws of Sines and Cosines.
Maths Challenge
Maths challenge.net: Corner Circle
This is a "three star" geometry problem where prior knowledge of circles and triangles is recommended to solve this circle in the corner problem.
CK-12 Foundation
Ck 12: Trigonometry: Law of Sines
[Free Registration/Login may be required to access all resource tools.] Learn how to use the Law of Sines with different types of triangles.
Alabama Learning Exchange
Alex: The Pythagorean Theorem in the Real World
The introduction of this lesson has students verifying the famous Pythagorean Theorem with a hands-on proof. Students will then apply the Theorem in one of two ways: by solving for the side lengths of a right triangle and by determining...
Illustrative Mathematics
Illustrative Mathematics: G Srt, G Mg How Far Is the Horizon?
Some friends are at the beach looking out onto the ocean on a clear day and they wonder how far away the horizon is. A second problem asks how far the horizon would be from the top of a mountain. Students must also answer a question...
Khan Academy
Khan Academy: Pythagorean Theorem Word Problems
Use the Pythagorean theorem to solve word problems. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
Khan Academy
Khan Academy: Use Area of Squares to Visualize Pythagorean Theorem
Apply the Pythagorean theorem and its converse to solve these problems. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
University of Cambridge
University of Cambridge: Nrich: Disappearing Square
This one page website explains how to find the area of a triangle with an interactive graphic. It then offers a challenge. The solution is available right at the website.
University of Cambridge
University of Cambridge: Nrich: Magic Triangle
Use your problems solving skills to make everything add up correctly for this challenge. The solution is right at this one page website.