"sửa góc y0=yoz"
\(\left\{{}\begin{matrix}\widehat{xoy}+\widehat{yoz}=180^0\\\widehat{yoz}=\widehat{xoz}-\widehat{xoy}=180^0-100=80^o\\\widehat{xot}+\widehat{toy}=\widehat{xoy}=100^0\\\widehat{xot}=\widehat{toy}=\dfrac{100^o}{2}=50^0\end{matrix}\right.\)