dec·a·gon
noun/ˈdekəɡən/
/ˈdekəɡɑːn/
(geometry)- a flat shape with ten straight sides and ten angles
十边形；十角形 Word Originmid 17th cent.: via medieval Latin from Greek dekagōnon, neuter (used as a noun) of dekagōnos ‘ten-angled’.