Pythagoras...

In addition to attending the conference at the Cedars School for Excellence in Greenock, Scotland which I blogged about earlier, I gave talks at two mathematics conferences. At both the Northwest Mathematics Conference in Portland, OR and at the California Mathematics Council - Southern Division Conference in Palm Springs, CA I gave a talk entitled Back to Basics - The Pythagorean Theorem. The premise was that the Pythagorean theorem is not only one of the oldest theorems in mathematics but is also one of the most basic and widely used theorems in secondary school mathematics. If one peruses the mathematics materials used at Phillips Exeter Academy (once on the Mathematics department page, click on Teaching Materials), it is astonishing at how many times the Pythagorean theorem makes an appearance...from Alex in the desert to determining the depth of a lake by yanking on a lily pad to calculating just how far it is to the horizon when standing atop Mt. Washington. Some applications are obvious, some subtle. At any rate, whether you teach mathematics or not, I thought you might enjoy these Pythagorean Fun Facts:


The Pythagorean Theorem - In any right triangle, the area of the square whose side is the hypotenuse is equal to the sum of the areas of the squares whose sides are the two legs.

• The book The Pythagorean Proposition contains 370 proofs.
• An algebraic proof was published by U.S. President James A. Garfield
• There is debate as to whether the theorem was discovered once, or many times in many places.
• The earliest reference to the theorem was in the Egyptian papyrus Berlin 6619 written between 2000 and 1786 B.C.E.
• Pythagoras lived from 569 to 475 B.C.E.
• Pythagoras used algebraic methods to construct, um, Pythagorean triples.
• Around 400 B.C.E. Plato gave a method for finding Pythagorean triples using algebra and geometry.
• Around 300 B.C.E., in Euclid's Elements, the oldest known extant proof of the theorem is presented.
• A verse of the Major-General's Song in the comic opera The Pirates of Penzance makes an oblique reference to the Pythagorean theorem.
• The Scarecrow in the Wizard of Oz makes a more specific reference to the theorem, misstating it.
• Greece, Japan, San Marino, Sierra Leone, and Suriname have issued postage stamps depicting Pythagoras and the theorem.
• In 2000, Uganda released a coin with the shape of an isosceles right triangle. The coins tail has an image of Pythagoras.
• In Neal Stephenson's book Anathem, the Pythagorean theorem is referred to as 'the Adrakhonic theorem'. A geometric proof is displayed on the side of an alien ship to display the aliens' understanding of mathematics. 

Source: Wikipedia


And, a review of two books on Pythagoras in the London Review of Books.