Where does “ペンタゴン” come from?
ペンタゴン (Japanese) comes from English Pentagon, from Middle French pentagone, from Late Latin pentagonum, from Ancient Greek πεντάγωνον, from Ancient Greek πεντάγωνος, from Ancient Greek γωνία, from Ancient Greek γόνυ, from Proto-Hellenic gónu — knee.
Ancestry of “ペンタゴン”, step by step