Cho \(\Delta ABC=\Delta DEF\). Biết \(\widehat{A}=32^0\), \(\widehat{F}=78^0\). Tính \(\widehat{B}\), \(\widehat{E}\)?
\(\widehat{B}=\widehat{E}=60^0\).\(\widehat{B}=60^0\), \(\widehat{E}=70^0\).\(\widehat{B}=\widehat{E}=78^0\).\(\widehat{B}=\widehat{E}=70^0\).Hướng dẫn giải:Ta có \(\Delta ABC=\Delta DEF\)
\(\Rightarrow\) \(\widehat{A}=\widehat{D}=32^0\) ; \(\widehat{B}=\widehat{E}\) ; \(\widehat{C}=\widehat{F}=78^0\) (các góc tương ứng bằng nhau)
Xét trong \(\Delta ABC\) có \(\widehat{A}+\widehat{B}+\widehat{C}=180^0\) \(\Rightarrow\) \(\widehat{B}=180^0-\widehat{A}-\widehat{C}=180^0-32^0-78^0=70^0\)
\(\Rightarrow\) \(\widehat{B}=\widehat{E}=70^0\)
