凹多角形 おうたかくけい Meanings Noun concave polygon; non-convex polygon See also: 凸多角形 (とつたかくけい). Kanji 凹 concave. Read as オウ. 多 many 角 angle. Read as カク. 形 shape. Read as ケイ. Word lists Geometry Jinuma: Japanese Dictionary · Word lists