Curated OER
Proof of the Pythagorean Theorem Using Transformations
Middle and high schoolers construct a triangle using Cabri Jr. They construct squares on each of the legs and hypotenuse of the triangle. Pupils show that the area of the squares on the leg equal the area of the square on the hypotenuse.
Shodor Education Foundation
Squaring the Triangle
Teach budding mathematicians how to square a triangle with an interactive that shows a graphical proof of the Pythagorean Theorem. Pupils alter the lengths of the legs using sliders. Using the inputted lengths, the applet displays the...
Curated OER
Right Triangles
Learners classify triangles and make connections regarding angle measurements and attributes of acute, right, and obtuse triangles. They listen to teacher define and explain triangles. Everyone imagines a place where a broken wing for a...
Illustrative Mathematics
Why Does SSS Work?
While it may seem incredibly obvious to the geometry student that congruent sides make congruent triangles, the proving of this by definition actually takes a bit of work. This exercise steps the class through this kind of proof by...
Curated OER
Pythagorean Theorem Proof
Tenth graders investigate the Pythagorean Theorem. Then they type up a formal paragraph proof of a proof of their choice.
Curated OER
Picking Pythagoras
Students discover that side measurement is used in determining angle classification of a triangle. By squaring sides, they predict whether triangles be right, obtuse, or acute. They prove the Pythagorean Theorem and use it to solve...
Curated OER
The Shortest Distance
Students, working on their GED, examine the steps used to resolve the unknown sides of a right triangle. They express the square root function as an exponential function and derive the distance formula using principles of geometry.
Curated OER
Building Big and Strong
Middle and high schoolers explore the concepts of architectural rigidity. They analyze a variety of polygons, and explain why some shapes add more strength to structures than others. The PBS video, "Building Big," is utilized in this plan.
Cuemath
Cuemath: Triangle Inequality Theorem
This lesson explores triangle inequality theorem, triangle inequality theorem-proof, and triangle inequality theorem problems. Try the hands-on triangle inequality theorem calculator and interactive problems to have a better...
Cuemath
Cuemath: Midsegment of a Triangle
This mini-lesson explores the world of the midsegment of a triangle by finding the answers to questions like what is midsegment of a triangle, triangle midsegment theorem, and proof with the help of interactive questions.
Science Buddies
Science Buddies: Circumscribing a Circle About a Triangle
Here is a project that combines Computer Science and Mathematics. Prove a method for circumscribing a circle about a triangle (as shown). You'll also learn how to create an interactive diagram to illustrate your proof, using an applet...
Science Buddies
Science Buddies: Inscribing a Circle in a Triangle Using the Geometry Applet
Here is a project that combines Computer Science and Mathematics. Prove a method for inscribing a circle within a triangle (as shown). You'll also learn how to create an interactive diagram to illustrate your proof, using an applet that...
Science Buddies
Science Buddies: Tangent Circles and Triangles
Here is a project that combines Computer Science and Mathematics. The two circles are tangent to one another at point A. Their diameters are parallel. Prove that points A, D and F are co-linear. You'll also learn how to create an...
Science Buddies
Science Buddies: Circles, Tangent Lines and Triangles
Here is a project that combines Computer Science and Mathematics. The semicircle has two tangent lines that meet at point T. You need to prove that a line drawn from A to T bisects CD. You'll also learn how to create an interactive...
CK-12 Foundation
Ck 12: Interactive Geometry: 1.7 the Pythagorean Theorem
Explore and discover the Pythagorean theorem.
Other
Radford University: Law of Sines
This page states the Law of Sines and provides some interactive graphics that may help you understand the law more clearly.
CK-12 Foundation
Ck 12: Geometry: Pythagorean Theorem and Pythagorean Triples
[Free Registration/Login may be required to access all resource tools.] Apply the Pythagorean Theorem and its converse. Includes videos, exercises, links to interactive activities, etc.
ClassFlow
Class Flow: Cpctc
[Free Registration/Login Required] This flipchart looks into the concept of CPCTC with triangles, using proofs. This flipchart has interactive parts, video, and voting.