Vedic Altar Geometry, c. 800 - 500 BCEThe Shulba Sutras are ritual construction manuals. A fire altar had to be rebuilt in a different shape while keeping exactly the same area — square into circle, and back again. This requires a working value for the square root of two, and for pi. Achieved without the relation we call the Pythagorean theorem. It is in these texts, in India, before Pythagoras. Building instructions, not philosophy.