\(a.\)
\(\Delta ABC\) cân tại \(A\Rightarrow\widehat{C}=\widehat{B}=55^0\)
Vậy \(\widehat{C}=55^0\)
\(a.\)
\(\Delta ABC\) vuông tại \(A\Rightarrow\widehat{A}=90^0\)
\(\Delta ABC\) có : \(\widehat{A}+\widehat{B}+\widehat{C}=180^0\)
\(\Rightarrow90^0+55^0+\widehat{C}=180^0\)
\(\Rightarrow\widehat{C}=180^0-\left(90^0-55^0\right)=35^0\)
Vậy \(\widehat{C}=35^0\)