[tex]\text{Apply sine rule,}\\\\~~~~~~~~\dfrac{a}{\sin A} = \dfrac{b}{\sin B} = \dfrac{c}{\sin C}\\\\\\\implies \dfrac{b }{\sin B} = \dfrac{c}{ \sin C}\\\\\\\implies b = \dfrac{c \cdot \sin B}{\sin C}\\\\\\\implies b = \dfrac{197\sin 52^\circ}{\sin 51^{\circ}}~~~~~~~~~;\left[\angle C = 180^{\circ} - 77^{\circ} -52^{\circ} = 51^{\circ} \right]\\\\\\\implies b \approx 200[/tex]
