Chapter 12.7, Problem 12WE

To determine

To solve the given triangle ABC.

Answer to Problem 12WE

  $B={28.1}^{\circ }$

Explanation of Solution

Given information :

  

According to law of sines,

In any triangle ABC,

  

  $\frac{a}{\sin A}=\frac{b}{\sin B}=\frac{c}{\sin C}$

Hence,

  $\begin{array}{l}\frac{15}{\sin {40}^{\circ }}=\frac{11}{\sin B}\\ \sin B=\frac{\sin {40}^{\circ }\times 11}{15}\\ B={\sin }^{-1}0.4713\\ B={28.1}^{\circ }\end{array}$