Gougu

The Pythagorean theorem was in use well before its actual proof by Pythagoras
(6th century BC), and later, Euclid (4th century BC). In Asia, the proof that nails it
is called Gougu ( from base and altitude),and is figured below.

The reference triangle (in green), sees its various sides projected differently than we are
used to: he hypotenuse goes under the triangle towards the back, and the short side
toward the top. The third side is the usual projection.

It is then a matter of fitting the pieces, as in a puzzle.
The yellows, the blue and the pinks, in order.

Les neufs chapitres sur l'art mathématique. (Beween years -100 and 50).

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