Translation:My friend has a scientific question about the dance.
On the news recently (2018-05-22): Doctors explain Michael Jackson's impossible dance move
해 is the contraction of 하여.
관하다 is an adjective-like verb roughly meaning "to be about" or "to concern".
관해 is the form you'd use before verbs, e.g. 음식에 관해 생각하다 means "to think about food".
관한 is the verbal modifier form that goes before nouns, e.g. 음식에 관한 책 means "book about food".
관해/관한 can be replaced by 대해/대한