Egypt: The Golden Ratio, Right Triangles, and Pyramid Volumes
Babylonian Right Triangle Explorations
Greece: The School of Pythagoras
It is a valuable tool in geography and engineering because if you can measure one angle and the distance between three points, or two angles and the distance between two points, you can deduce the measurement of all the distances, all the angles, and the related areas.
For architecture roofing projects:
George Washington used the Pythagorean Theorem as a land surveyor before becoming militia captain, planter, Revolutionary War general, and president.