The error is that, for example, the side with five nuts means that it is four segments long, not five, because of where the nuts are placed (nuts at the endpoint of the lines). The triangle is a 2-3-4 in this image, which is impossible because that is not a right triangle.

The problem is that there is an obvious interpretation (count the nuts) and a less obvious interpretation (count the spaces between the nuts) and if you don't see the less obvious interpretation immediately the people who see it will claim it's the obvious interpretation and you're a mathematical ignoramous for not noticing it immediately, as they did.

In truth that's probably coming from people who didn't immediately notice the obvious interpretation and had to squeeze their noggin hard to get it, and then got upset that they found it that hard and squeezed their nogging even more to find a less obvious interpretation to hold up and say "see, that's why I was confused, you're all wrong".

I'm being very mean in this thread. It's because it's all a big example of the Ludic (sic) fallacy, that I just learned about today and can't stop laughing.

https://en.wikipedia.org/wiki/Ludic_fallacy

I would not claim it's more obvious, but this is an illustration on the cover of a mathematics journal. It should show mathematics, not an artistic misunderstanding. If people have to stop and think through the math to understand it, then it is doing its job properly. As it is, it just gives a bad name to the artistically minded.

You can think through the maths but you don't have to. This is one of those cases were pattern recognition is enough and no more thought is needed. That is to say, a mathematician should (and has no excuse not to) have seen Euclid's illustration of Pythagora's theorem which the journal cover is a very obvious representation of, so there should be no confusion.

It does make you stop and think. That was the artist's stated goal, and why they named it as they did.

> The problem is that there is an obvious interpretation (count the nuts) and a less obvious interpretation (count the spaces between the nuts)

Only if one goes with your "obvious" interpretation the artwork should obviously not be called anything to do with Pythagoras, since his theorem is about side lenghts, i.e. lines (spaces). Not points (nuts).

The problem is that the marks seem to imply that a 2-3-4 triangle is a right triangle, when in fact they’re just unevenly spaced.

To illustrate the theorem, each stone would need to account for the same amount of area, which the ones on the edges don’t do.