myEtymology.com: Greek etymology of pentagonon

Etymology of the Greek word pentagonon (πεντάγωνον)

the Greek word pentagonon, πεντάγωνον

using the Greek prefix penta-, πεντα-, πέντα-

derived from the Late Greek word pente, πέντε ('five')

derived from the Proto-Indo-European root *penkʷe

using the Greek suffix -gonon, -γωνον

derived from the Greek word gonia, γωνία (angle; an angle)

derived from the Proto-Indo-European root *genu-