## Precalculus (6th Edition) Blitzer

The value of b to the nearest tenth is $92.9$.
By using the sine rule, \begin{align} & \frac{\sin {{12}^{{}^\circ }}}{20}=\frac{\sin {{75}^{{}^\circ }}}{b} \\ & b=\frac{20\times \sin {{75}^{{}^\circ }}}{\sin {{12}^{{}^\circ }}} \\ & b=\frac{20\times 0.96}{0.20} \\ & b\approx 92.8 \end{align} Hence, b is approximately $92.9$.