a) \(\widehat{xOy}=180^o;\widehat{yOz}=60^0\)
\(\Rightarrow\widehat{xOz}=\widehat{xOy}-\widehat{yOz}=180^o-60^o=120^o\)
\(\Rightarrow\widehat{xOz}=120^o\)
b) hai góc \(\widehat{zOm}\)và \(\widehat{zOn}\)là hai góc phụ nhau
giải thích : \(\widehat{zOm}=\widehat{\frac{xOz}{2}}=\frac{120}{2}=60^o\)
\(\widehat{zOn}=\widehat{\frac{yOz}{2}}=\frac{60}{2}=30^o\)
do\(60^o+30^o=90^o\)nên \(\widehat{zOm}\)và \(\widehat{zOn}\)là 2 góc phụ nhau