The rule relating the sides of a right triangle appears in an Indian ritual geometry text — before Pythagoras.
“The rope stretched along the diagonal of a rectangle makes an area that the vertical and horizontal sides make together.”
— Baudhāyana Śulba Sūtra (c. 800–600 BCE)
The Pythagorean theorem: a² + b² = c².
A genuine, defensible parallel.
The Śulba Sūtras are manuals for building fire-altars to exact specifications, and to get the geometry right they state, in words, the relationship we call the Pythagorean theorem — that the square on the diagonal equals the sum of the squares on the two sides. Baudhāyana also gives a strikingly accurate approximation of √2.
The honest framing: the *theorem* (as a statement of fact and a practical rule) clearly appears here, plausibly before Pythagoras (~570–495 BCE), and the Babylonians knew the relationship even earlier. What the Greeks added was the formal *proof* — the deductive demonstration that it holds for every right triangle. So this isn't 'India beat Greece' so much as a reminder that the result was discovered independently in several civilisations, with the Vedic priests arriving via the very practical need to lay out sacred altars precisely.