https://cdn.britannica.com/43/70143-004-CCB17706/theorem-dem...
It is not immediately obvious why the area of the hypotenuse square should be equal to the sum of the areas of squares drawn on the other two sides of the triangle.
It is clear that the lengths of a, b and c are connected -- if we are given the length of any two of (a, b, c), and one angle, then the remaining side can only have one possible length.
So far, so simple; what is less clear is why the exact relationship for right triangles is c^2 = a^2 + b^2.
The other proofs demonstrate that the relationship holds, but give little insight.
The geometric proof linked above makes the relationship crystal-clear.
For any right triangle we can define a 'big square' with sides (a + b). The hypotenuse square is simply the area of the 'big square' with 4 copies of the original triangle removed.
Simple algebra then gives us the formula for the hypotenuse square:
The big square has area: (a+b)^2 = a^2 + 2ab + b^2
The original triangle has area: ab/2
1 big square minus four original triangles has area: (a+b)^2 - 4ab/2 = a^2 + b^2
Similarly, if you take the hypotenuse square, and subtract 4 copies of the original triangle, you get a square with sides (b - a). This is trivial to prove with algebra but the geometric visualisation is quite neat, and makes clear why the hypotenuse square must always equal the sum of the other two squares.
I’m amazed by how many people I meet who don’t know about his contribution to the discovery and development of tonality! You mean the triangle guy invented music???
I own a coin designed by Pythagoras. Well, it’s from 510 BC Croton, features the tripod from Delphi, and has little snakes at the bottom. Also 10 little dots. No tetractys, but that’d be a bit much. Also, the front is the opposite of the back (Aristotle describes the Pythagorean obsession with opposites).
I mean, maybe it wasn't Pythagoras — but his father was a gold smith and it is the most beautiful coin of the era, suggesting genius. But it might have been Hippasus, who was known for having conducted the first hypothesis driven experiment of all time: casting bronze chimes in musical proportions to see if the 1:2:3:4 intervals that make stringed music consonant apply with the thickness of chimes. They do. The mathematical model generalizes.
Currently, I’m working on a textbook callout that helps students learn about fractions using musical intervals — and introduces all the DEI glory of Pythagoras (multiethnic, gender-mixed community, credited his moral doctrines to a woman, Themistoclea of Delphi, etc). I’m leaving out the fact that he was kicked out of the boys Olympics when he was 16 for being too effeminate. He won the men’s Olympics in boxing, introducing some kind of new martial arts. Then he trained the most successful Olympic athlete of all time, Milo of Croton, who won 5 consecutive Olympics. No one has done that since.
Let me know if you need sources for any of these facts, I collect them all. Pythagoras is the bessst
(also between this and Plato's failed Olympic career I feel like there's a lot more to the ancient Greek Olympic games than I'm aware of)
Unrelated, but that's generally true.
... You know that we've found flutes in perfect pentatonic tuning that date back at least 40,000 years right (in Germany, Slovenia, etc)?
Pythagoras certainly contributed but to say he 'invented music' you'd have to ignore tens of thousands of years of history.
People were also using 'his' theorem long before he was ever born. Not trynna diminish the guy but let's give the ancestors their due.
It’s impossible to know the true scope of how it was all made whether it’s Pythagoras and the origin of tonality or Bach and the birth of common practice. There should always be a ‘click here to go deeper down the rabbit hole’ option, but sometimes Pythagoras and Bach are easy focal points to begin delivering the concept that this all came from somewhere.
https://www.youtube.com/watch?v=VHeWndnHuQs
What isn't stressed enough is that they both came up with their respective proofs independently.
They just happened to have the same teacher...
Their school is phenomenal, https://www.cbsnews.com/news/the-inspiration-for-new-orleans...
> Rogers told Whitaker that Calcea and Ne'Kiya are not "unicorns." She said all the young ladies at St. Mary's are exceptional and are taught early that they can achieve great things. For the last 17 years, St. Mary's Academy has had a 100% graduation rate and a 100% college admission rate.
What is so counter-intuitive to me is that if the authors had wanted to earn $500 (or $250 after splitting it) they could have just got a job at McDonalds. They would have earned that money with far less time and effort.
I'm kinda glad that nobody pointed that out to them though :-)
But Prize-awards seems to put us into an entirely different economic frame. You can't say they did it just for the recognition, because if the prize wasn't there they wouldn't have bothered. But you also can't say that they did it for the money, because the money was ludicrously low--even when valued at the rate of unskilled labor.
Prize or not, time 'invested' in reasoning out an original solution will very likely 'pay off' in the future much better than investing in flipping burgers. In satisfaction and fulfillment for sure. What's life for? No doubt Erdos and Euler, and certainly van Gogh, might have made more at McDonalds as well.
It's easy for anybody to see that, say climbing a mountain with a death rate of >1% is challenging, or completing an ultramarathon; so no prizes need to be offered. Offering a monetary prize for illegible things like new math proofs creates common knowledge that those things are challenging and worthwhile.
> far less time and effort
Pick one
https://en.wikipedia.org/wiki/Divine_Proportions:_Rational_T...
Apropos of nothing, just saying, and this thread is a great example.
I always want to read more books after a good dose of hacker news.
Tongue firmly planted in cheek. :)
Apropos of nothing, just saying, and this thread is a great example.
I always want to read more books after a good dose of hacker news.
However, I just cannot get excited about an article with proofs that:
(1) give a different name for methods that use sin(90)=1 vs only working with sine of an acute angle ("cyclometric" vs "trigonometric", ugh)
(2) use "high-powered" methods like convergence of infinite geometric series to prove the Pythagorean theorem
(3) apply the law of sines several times to produce the Pythagorean theorem
I just couldn't give it a chance. Give me a good old fashioned proof by a dissection diagram any day.
If anything, "trigonometric" is the word they should have avoided, since, even though the word is etymologocally closely associated with triangles as they said, it is also commonly used to refer to exactly the thing they are trying to avoid -- dependency on the Pythagorian theorem, which was the spource of all the confusion and fuss and terrible media reporting when they first published their proof and referred to an ill-defined statement in a 100 year old textbook.
There are hundreds of old proofs of Pythagorean Theorem. I'm sure you can find one that satisfies you. For those of us who enjoy new ideas that push back the intellectual frontier, this paper is very nice.
it's cyclotopic, a term they coined. I suggest the intro section juxtaposing trigonometry vs 'circular' approaches might best be read as guidance as to how interested high school students (their past selves?) might think about the topic rather than a necessary preface for their paper.
I also very much enjoyed: "In this section, we verify that our proofs aren’t circular."
And articles like this have been popping up for years (I think about the exact same two students even), and each time I have to decide whether to downplay the scale of their achievement so high school students don't lose hope about achieving something similar, or praise them with the qualifier for high school students because they couldn't be expected to have enough mathematical background to push the boundaries of one of the oldest and most extensively researched parts of modern mathematics.
I can't help but feel that each additional article is just further entrenching the stereotype that you're either a genius at mathematics or not, and is demotivating the students in question, because how on earth are they ever going to top this?