It is uncertain why the Pythagorean theorem is so named; it was neither Pythagoras nor his followers who discovered or even proved the rule, nor were they even particularly concerned with it in any way.
Sexual position where the woman is being penetrated sideways while the guy is on his knees and one of her legs ends up on the guy's shoulder; hence, a rough geometrical triangular shape is formed. Also know as the RC kick.
Note that this position is often use in BD sessions to hin the woman and at the same time establish that the guy is the man (hedeman). It is more pleasurable is done with a baldey.