TED Talks
Ted: Ted Ed: How Many Ways Are There to Prove the Pythagorean Theorem?
Betty Fei details these three famous Pythagorean theorem proofs.
National Council of Teachers of Mathematics
Nctm: Illuminations: Proof Without Words: Pythagorean Theorem
This applet proves the Pythagorean Theorem "without words" using geometry.
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...
Texas Instruments
Texas Instruments: Proof of the Pythagorean Theorem Using Transformations
In this activity, students will explore visual proofs of the Pythagorean Theorem using area and transformations. They will use the Cabri Jr. app to perform translations on the squares constructed on the two legs and the hypotenuse of a...
Science Education Resource Center at Carleton College
Serc: Pythagorean Theorem Investigations
In this activity, students will gain an understanding of the Pythagorean theorem and will recognize the variety of ways in which theorems can be proved algebraically, geometrically and visually.
PBS
Using the Pythagorean Puzzle
A printable expercise for students to find that the Pythagorean Theorem works. There are links to problems solving problems using the formula.
Cut the Knot
Cut the Knot!: Pythagoras' Theorem
This site explains the Pythagorean theorem, giving a proof from Euclid, and gives a great interactive visual aid with a good explanation with it.
University of British Columbia
University of British Columbia: Proof of the Pythagorean Theorem
A geometric model that proves the Pythagorean Theorem in a step-by-step diagram that students can advance at their own pace. Requires Java.
Alabama Learning Exchange
Alex: The Pythagorean Theorem in the Real World
The introduction of this lesson plan 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...
Alabama Learning Exchange
Alex: Growing in a Triangle
Middle school students explore the Pythagorean Theorem by measuring and calculating diagonal lengths using the Pythagorean Theorem. Students view an animated proof of the Pythagorean Theorem. They access an Internet site to view and...
Curated OER
Math Open Reference: Biography of Pythagoras
Biography of Greek mathematician, Pythagoras, who lived from 569 BC to approximately 475 BC. His theory, known as the Pythagorean Theorem continues to be of interest to mathematicians and has more than 400 different proofs.