Chapter 12.7, Problem 7P

To determine

To determine the length of AB.

Answer to Problem 7P

AB is 47.1 m

Explanation of Solution

Given information :

AC= 25 m

Angle A is ${85}^{\circ }$

Angle C is ${66}^{\circ }$

  

Here $\angle B={29}^{\circ }$

We have to find AB.

Now according to law of sines,

In any triangle ABC,

  

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

Hence,

  $\begin{array}{l}\frac{25}{\sin {29}^{\circ }}=\frac{AB}{\sin {66}^{\circ }}\\ PR=\frac{\sin {66}^{\circ }\times 25}{\sin {29}^{\circ }}\\ PR=47.1\end{array}$

Hence AB is 47.1 m.