Chapter 12.8, Problem 15OE

To determine

Give the name of law that can be used first to solve the triangle if the measurements are $a=12,b=11\text{ and }\angle A=35°$ .

Answer to Problem 15OE

The law of sine is used first for triangle which has $a=12,b=11\text{ and }\angle A=35°$ .

Explanation of Solution

Given information: The given measurements of triangle are $a=12,b=11\text{ and }\angle A=35°$ .

Calculation: Since the given triangle has $a=12,b=11\text{ and }\angle A=35°$ . Therefore the given triangle has the case of SSA (side-side-angle) where $\left(\angle A\right)$ is opposite angle to side $\left(a\right)$ . Therefore first apply law of sine for angle $\left(\angle A\right)$ to find the missing angle $\left(\angle B\right)$ first and then other formulas can be used to determine the remaining parameters of the given triangle.