\(\widehat{A}=180^0-\left(\widehat{B}+\widehat{C}\right)=105^0\)
Áp dụng định lý hàm sin:
\(\dfrac{BC}{sin\widehat{A}}=\dfrac{AC}{sin\widehat{B}}=\dfrac{AB}{sin\widehat{C}}\Rightarrow\left\{{}\begin{matrix}AB=\dfrac{BC.sin\widehat{C}}{sin\widehat{A}}\approx14,64\left(cm\right)\\AC=\dfrac{BC.sin\widehat{B}}{sin\widehat{A}}\approx10,35\left(cm\right)\end{matrix}\right.\)