 "Triangle" was directed by Yoo Cheol-yong and written by Choi Wan-kyu, who previously collaborated on the gambling dramas "All In" (2003) and "Swallow the Sun" (2009).Separated in childhood by unfortunate circumstances, three brothers meet twenty years later, unaware of their connection to each other.Jang Dong-soo, Jang Dong-chul and Jang Dong-woo are three brothers who got separated at a young age after their father died and their mother left them.