Question

Trl hộ mk câu a thui đc r câu b bk làm :))) tks

Answer 1

a: Ta có: \(\widehat{xBC}=\widehat{ABM}\)

mà \(\widehat{ABM}=\widehat{NMB}\)

nên \(\widehat{xBC}=\widehat{BMN}\)