\(\Delta ABC.deu\Rightarrow\widehat{A}=\widehat{B}=\widehat{C}=\frac{180^o}{3}=60^o\) (do tong so do 3 goc cua 1 tam giac =180 o )
Study well
Tam giác ABC đều
\(\Rightarrow\widehat{A}=\widebat{B}=\widehat{C}\)
Mà \(\widehat{A}+\widehat{B}+\widehat{C}=180^o\)
\(\Rightarrow\widehat{A}=\widehat{B}=\widehat{C}=\frac{180}{3}=60^0\)