"The Chinese Proof" of the Pythagorean theorem (the little orange square is
a², the medium orange square is
b², and the large orange square is
The righthand picture above appears in the Chou pei suan ching 周髀算經 (ca. 1100 B.C.), for the special (3,4,5) pythagorean triple….
…the earliest known proof of Pythagoras is given by Zhoubi suanjing (The Arithmetical Classic of the Gnomon and the Circular Paths of Heaven) (c. 100 B.C.E.-c. 100 C.E.)
[T]his proof, with the exclamation `Behold!’, is due to the Indian mathematician Bhaskara II (approx. 1114-1185) …
Jöran Friberg … presented convincing evidence that the … Babylonians were aware of the Pythagoras theorem around 1800 B.C.E.