Ban tu ve hinh nhe
Vi goc xOy va yOz la 2 goc ke bu
=>xOy+yOz=180o
Thay goc xOy=100o
Ta co:100o+yOz=180o
=>yOz=180o-1000=80o
Vay so do goc yOz = 80o
Vì \(\widehat{xOy}\) và \(\widehat{yOz}\) là hai góc kề bù
\(\Rightarrow\widehat{xOy}+\widehat{yOz}=180^o\)
Thay \(\widehat{xOy}=100^o\), ta có:
\(100^o+\widehat{yOz}=180^o\)
\(\Rightarrow\widehat{yOz}=180^o-100^o\)
\(\Rightarrow\widehat{yOz}=80^o\)
Vậy \(\widehat{yOz}=80^o\)