Meep's Math Matters 4: the Pythagoream Theorem

In this, the fourth episode of Meep's Math Matters, I present my favorite proof of the Pythagorean Theorem. There are hundreds of proofs for this theorem (albeit many only minor variations of each other), and 75 of them can be found at http://www.cut-the-knot.org/pythagoras/index.shtml -- which one is your favorite?

I can be contacted at marypat.campbell@gmail.com. Remember to spread the math love!

Category:

Education

Tags:

• math
• classic
• geometry
• Pythagoras
• Pythagorean
• theorem

[jupiterjjrm]

In 4:50 how about justifying the 90 deg. by a symmetry argument using a 90dg. rotation on the square? I'd use either argument, but this one probably works better for eager students.

[meepsmathmatters]

There are lots of ways to skin this cat.

Actually, if you're teaching, it's a good idea to show more than one proof of this theorem, just to show that while there's only one answer to the problem (in that, the pythagorean theorem is true), there are lots of ways to get to that answer.

[geomong]

Oh, what a beautiful proof. But, excuse me what Q.E.D. does mean? Thank you very much.

[meepsmathmatters]

Q.E.D. literally means "quod erat demonstrandum", Latin for (roughly) "I have demonstrated that", meaning "the proof is finished".

It's a common way to indicate the end of a mathematical proof.

[jupiterjjrm]

I have lost count of the number of coffee+Bailey's I've earnt during my teens with this proof and some triangular number tricks! ;D Who would have thought this kind of stuff would be so useful in bars with people who have long hated maths?! I swear it works! It can even be sexy!

[meepsmathmatters]

Yay for Irish coffee!

[adamennis999]

never heard of them being called legs

[jupiterjjrm]

LOL