Ta có: $\widehat{A}=180^{\circ}-\widehat{B}-\widehat{C}=180^{\circ}-83^{\circ}-57^{\circ}=40^{\circ}$
Áp dụng định lí sin: $\frac{a}{\sin A}=\frac{b}{\sin B}=\frac{c}{\sin C}=2R$
=> $R=\frac{a}{2\sin A}\approx 106,96 (cm)$
=> $b = 2R.sin B = 2.106,96.\sin 83^{\circ} = 212,33 cm$
=> $c = 2R.sin C = 2.106,96.\sin 57^{\circ} = 179,41 cm$