Oswego City School District
Regents Exam Prep Center: Pythagorean Theorem
Material to supplement introductory instruction on the Pythagorean Theorem. A very simple look at its use in geometry, a multiple-choice quiz through which students can test themselves and check their answers, and a teacher resource...
National Council of Teachers of Mathematics
Nctm: Illuminations: Proof Without Words: Pythagorean Theorem
This applet proves the Pythagorean Theorem "without words" using geometry.
TED Talks
Ted: Ted Ed: How Many Ways Are There to Prove the Pythagorean Theorem?
Betty Fei details these three famous Pythagorean theorem proofs.
CK-12 Foundation
Ck 12: Interactive Geometry: 1.7 the Pythagorean Theorem
Explore and discover the Pythagorean theorem.
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...
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.
Cut the Knot
Cut the Knot!: Analogues and Generalization of the Pythagorean Theorem
This site discusses the theorems and other findings which are directly related to the fundamental Pythagorean theorem. Be sure to click on the link to information on Pythagorean theorem to find several proofs of the theorem.
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...
Cuemath
Cuemath: Hypotenuse Leg Theorem
Explore the world of the hypotenuse leg theorem in this mini-lesson. Provides a definition, examples, and practice questions with answers that help with understanding their properties.
Math Is Fun
Math Is Fun: Pythagoras' Theorem
This resource investigates the Pythagorean Theorem. Includes animations, examples, proofs, and links to problems and activities.
Shodor Education Foundation
Shodor Interactivate: Squaring the Triangle
Learn about how the Pythagorean Theorem works through investigating the standard geometric proof.
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...
Math Open Reference
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.
Cut the Knot
Cut the Knot!: The Law of Cosines (Cosine Rule)
This site from Cut The Knot provides an overview of the law of cosines, complete with an explanation of the law and a proof of the law.
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.