a)
Vì \(\widehat{yOz}\)kề phụ vs \(\widehat{xOy}\Rightarrow\widehat{yOz}+\widehat{xOy}=90^o\)mà \(\widehat{xOy}=35^o\Rightarrow\widehat{yOz}=90^o-35^o=55^o\)
B) Vì \(\widehat{mOn}\)kề bù vs \(\widehat{nOp}\Rightarrow\widehat{mOn}+\widehat{nOp}=180^o\)mà \(\widehat{mOn=}45^o\Rightarrow\widehat{nOp}=180^o-45^o=135^o\)