We can also assume the Greek mathematicians knew about the Sumerian and Babylonian maths. Maybe not in detail, but they probably knew what was possible and could then re-create the methods. I just finished a book titled 1177 BC The Year Civilization Collapsed. It discusses how the civilizations around the Mediterranean Sea were closely linked by trade, politics, marriage(!), and economics. So, the Babylonian/Sumerian advances in maths and astronomy were widely circulated back then, in all likelihood.

I remember reading they liked the number 60 for the number of factors it has, plus its association with the circle -- 360 degrees is coincidentally close to the number of days in a year.