Pythagoras, who is remembered for his theorem about the sides of a right-angled triangle, lived around 540 BC, while Euclid, the best known geometer of the ancient world, lived around 300 BC.

• 生活在公元前540年左右的毕达哥拉斯，便提出了闻名于世的关于直角三角形各边的勾股定理。 古代最知名的几何学家欧几里得生活在公元前300年左右。