We like to think we know who did what in early mathematics, but we really only know about Greeks whose compatriots took the trouble to write down their names.

We like to think we know who did what in early mathematics, but we really only know about Greeks whose compatriots took the trouble to write down their names. This particular result is contemporary with some of those selfsame Greeks. There is no telling which way advancements moved. Most likely it was both ways, by then. But there had been a long tradition of traveling to Egypt to learn geometry from the masters, and also of not naming foreigners one got things from. Going on two millennia later, Francis Bacon was scrupulous about reserving credit to Al-Haytham for inventing Science as we know it today. People following Bacon were not, so much.