Context?
Pythagoreans were a math sect, and irrational numbers went against their holy doctrine when a member of the sect proved them to exist.
Also, he wouldn’t let you eat beans
That sicks fuck

Although Pythogoras is probably just semi-historical. Pythogoras himself would probably have been quite excited about the revelation, but among other things his cult attributed basically all existing math to him while also doing a really, really bad job of preserving any of his actual writings.

Anyways, “his” theorum was being used in Babylon and Egypt centuries before his birth. He just popularized it in Greece.

different theorem? how do triangle sides have negative length?

Wrong class of numbers you’re thinking of. Irrational numbers are the ones that can’t be represented in fractions.

Example: A right triangle where both legs have length 1.

a^2^ + b^2^ =c^2^
1^2^ + 1^2^ =c^2^
1+1=c^2^
2=c^2^ => c = sqrt(2)