GT: \(\widehat{xOy}\) + \(\widehat{yOz}\) = 180o
\(\widehat{xOy}\) = \(\widehat{yOz}\)
KL: \(\widehat{xOy}\) = ?
\(\widehat{yOz}\) = ?
\(\widehat{xOy}\) + \(\widehat{yOz}\) = 180o (gt)
Mà: \(\widehat{xOy}\) = \(\widehat{yOz}\) (gt)
\(\Rightarrow\) \(\widehat{xOy}\) = \(\widehat{yOz}\) = \(\frac{180^o}{2}\) = 90o
Giải:
Ta có: \(\widehat{xOy}+\widehat{yOz}=180^o\) ( kề bù )
hay \(\widehat{xOy}+\widehat{xOy}=180^o\)
\(\Rightarrow2.\widehat{xOy}=180^o\)
\(\Rightarrow\widehat{xOy}=90^o\)
\(\Rightarrow\widehat{xOy}=\widehat{yOz}=90^o\)
Vậy \(\widehat{xOy}=\widehat{yOz}=90^o\)
Vì xOy và yOz là 2 góc kề bù
=> xOy + yOz = 180*
mà xOy = yOz
=> xOy = yOz = \(\sqrt{180}\) độ
=> xOy = yOz = 90*