Pentagon ( hangul : 펜타곤 ; stylized as PENTAGON and abbreviated as SGA ) is a male group South Korean formed by Cube Entertainment in 2016. The group is currently composed of nine members: Jinho, Hui, Hongseok, Shinwon, Yan An , Yeo One, Yuto, Kino and Wooseok, introduced through the reality show Pentagon Maker . Its official debut took place on October 10, 2016 with the launch of aextended play autointitulado.