Analysis of information sources in references of the Wikipedia article "Pythagorean theorem" in English language version.
The parallel postulate is equivalent to the Equidistance postulate, Playfair axiom, Proclus axiom, the Triangle postulate and the Pythagorean theorem.
Brief historical overview of the Pythagoras's theorem and its discoverer, Pythagoras. Simple proof of the result and discussion of some extensions.
... it is not until Euclid that we find a logical sequence of general theorems with proper proofs.
We could include ... the parallel postulate and derive the Pythagorean theorem. Or we could instead make the Pythagorean theorem among the other axioms and derive the parallel postulate.
It should now be clear that decisions about sources are crucial in addressing the question of whether Pythagoras was a mathematician and scientist. The view of Pythagoras's cosmos sketched in the first five paragraphs of this section, according to which he was neither a mathematician nor a scientist, remains the consensus.