The Sulvasutras are ancient Hindu texts from 600-300 BC that describe geometric constructions and formulas to help build Vedic altars. They contain some of the earliest concepts resembling the Pythagorean theorem and approximations of irrational numbers like the square root of 2. The Sulvasutras were created by Vedic priests and mathematicians to precisely lay out fire altars and ritual spaces according to religious ceremonies and principles of symmetry.