"It was a theory Pythagoras proved..."
It's not a scientific theory, it's a mathematical theorem. It can only be proved because the premises are axiomatic.
It was not axiomatic before Pythagoras...
So, mathematics is not science in your enlightened world view?
Indeed, Math and science are distinct fields of study, the former based on deductive logic, the latter on empirical observation.
Geometry is not science?
Once again, he stumbles upon the truth. Amazing, just amazing.