The US high school math curriculum relegates deductive proofs to a course in “geometry”, which typically ends up being a somewhat watered down version of Euclid

The US high school math curriculum relegates deductive proofs to a course in “geometry”, which typically ends up being a somewhat watered down version of Euclid, with a few extra topics tossed in at the end. Arguably there are better subjects to use for teaching deductive reasoning, and better formalizations for teaching geometry. This particular approach has a lot of historical inertia though.