Triangle (2014)

All involves three siblings separated when they were young due to the death of their parent. They met later both have desire to get revenge

Both dramas is about three brothers who reunite after many years, ever since the death of their parents. Both has same main actor Lee Bum Soo, and also has general similar feeling.

JaeJoong stars in both. Triangle was about him (not so) covertly taking over a city and a business. Spy - he worked for his country. Triangle was better IMO

Triangle is about brothers finding each other after years and the most powerful one is a gangster. K2H is about a prince learning to steer through danger and politics. Two very different dramas. In Triangle, the lead turns from a pitiful, poor, and powerless gangster to the most calculating, powerful one. He steers his people through danger and comes out on top. By the middle, there is no one who doesn't feel apprehension when they hear his name. In King2Hearts, the degenerate playboy prince transforms into a smart, respectable, highly admired leader. Also, in both, the leads were called 'trash' in the beginning.

they have similar things - casino's, revenge, poor people against a rich guy that killed their dad - a mining town - history - brothers that don't know they are brothers...ectra..

Similar premise. Both stories are about three brothers who lose their parents and become seperated as children. They reconnect later on without knowing who the other two are to them. Both action dramas.

The stories are somewhat different. But if you like Hotel king you'll definitely like Triangle. Both are based on protecting someone and the romance in both are good.

It was done by the same writer and director as Triangle. It is a really good story with Lee Byung Hun and Ji Sung and it is all about the world of casinos.

Again it is done by the same writer and director. There are casinos but also lots of explosions and exotic locations like Jeju, Africa and Las Vegas. Also starring Ji Sung.

Two brothers were separated because news reporters slandered their father. So they both want to take revenge. They finally meet each other after 13 years!

These 2 dramas are not related by having the same story, but for following one of the same concept: detectives and you can also see action and mystery in both. Let's not forget that both dramas are including characters with impressive stories.