Đáp án:
a) ta có : $$\widehat{aOm}$$ + $$\widehat{aOb}$$ = $$\widehat{bOm}$$
⇒ $$\widehat{bOm}$$ = $$200^\circ$$
ta có : $$\widehat{xOy}$$ = $$\widehat{aOb}$$ (2 góc d²)
mà $$\widehat{aOb}$$ = $$80^\circ$$ ⇒ $$\widehat{xOy}$$ = $$80^\circ$$
ta có : $$\widehat{aOm}$$ + $$\widehat{mOx}$$ = $$180^\circ$$ (2 góc kề bù)
⇒ $$\widehat{bOm}$$ = $$60^\circ$$
ta có : $$\widehat{aOy}$$ + $$\widehat{aOm}$$ = $$180^\circ$$ (2 góc kề bù)
⇒ $$\widehat{aOy}$$ = $$100^\circ$$
ta có : $$\widehat{xOz}$$ = $$\widehat{aOc}$$ (2 góc d²)
mà $$\widehat{aOc}$$ = $$40^\circ$$ ⇒ $$\widehat{xOz}$$ = $$40^\circ$$
ta có : $$\widehat{bOx}$$ + $$\widehat{aOb}$$ = $$180^\circ$$ (2 góc kề bù)
⇒ $$\widehat{bOx}$$ = $$100^\circ$$
ta có : $$\widehat{xOz}$$ + $$\widehat{bOx}$$ = $$\widehat{bOz}$$
⇒ $$\widehat{bOz}$$ = $$140^\circ$$
