Đáp án+Giải thích các bước giải:
a) Vì Ox, Oy là hai tia đối nhau
⇒ $\widehat{xOz}$ `+` $\widehat{yOz}$ `=` $180^o$
⇒ $30^o$ `+` $\widehat{yOz}$ `=` $180^o$
⇒ $\widehat{yOz}$ `=` $180^o$ `-` $30^o$ `=` $150^o$
b) Vì $\widehat{xOm}$ là góc vuông → $\widehat{xOm}$`=`$90^o$
⇒ $\widehat{xOm}$ `+` $\widehat{yOm}$ `=` $180^o$
⇒ $90^o$ `+` $\widehat{yOm}$ `=` $180^o$
⇒ $\widehat{yOm}$ `=` $180^o$ `-` $90^o$ `=` $110^o$
Ta có: $\widehat{xOm}$`=`$90^o$ ; $\widehat{xOz}$ `=` $30^o$
⇒ $\widehat{xOm}$ `-` $\widehat{xOz}$ `=` $\widehat{zOm}$
⇒ $90^o$ `-` $30^o$ `=` $60^o$
c) Vì Ot là tia phân giác của góc $\widehat{yOm}$
→ $\widehat{mOt}$ `=` $\widehat{tOy}$ `=` $\dfrac{\widehat{yOm}}{2}$ `=` $\dfrac{90^o}{2}$ `=` $45^o$
Ta có: $\widehat{mOt}$`=`$45^o$ ; $\widehat{xOm}$ `=` $60^o$
⇒ $\widehat{mOt}$ `+` $\widehat{xOm}$ `=` $\widehat{tOz}$
⇒ $45^o$ + $60^o$ = $95^o$
