$\widehat{A}-\widehat{B}={{22}^{0}}\Rightarrow \widehat{A}={{22}^{0}}+\widehat{B}$

$\widehat{B}-\widehat{C}={{22}^{0}}\Rightarrow \widehat{C}=\widehat{B}-{{22}^{0}}$

Mặt khác, tổng 3 góc trong một tam giác bằng 180$^{0}$ .

$\widehat{A}+\widehat{B}+\widehat{C}={{180}^{0}}$

${{22}^{0}}+\widehat{B}+\widehat{B}+\widehat{B}-{{22}^{0}}={{180}^{0}}$

$3\widehat{B}={{180}^{0}}\Rightarrow \widehat{B}={{60}^{0}}$

Suy ra $\widehat{A}={{82}^{0}}$