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# finding angle b in question 1?

-1
306
1

so here's the above question (i'm looking at #1), and the answer key:

the only thing i don't understand is how they got their final answer for B. I did 18 x sin 110 / 8, and did inverse sin and didn't get 53.7 but "DOMAIN error"

Dec 6, 2017

#1
+21191
+3

finding angle b in question 1?

$$\begin{array}{|rcll|} \hline \sin(B) &=& \frac{3.6}{4.2} \times \sin(110^{\circ}) \\ \sin(B) &=& 0.85714285714 \times 0.93969262079 \\ \sin(B) &=& 0.80545081782 \\\\ B &=& \arcsin(0.80545081782) \\ B &=& 53.6538157268^{\circ} \\\\ \mathbf{B} &\mathbf{=}& \mathbf{53.7^{\circ}} \\\\ A &=& 180^{\circ}- 110^{\circ} - 53.7^{\circ} \\ \mathbf{A} &\mathbf{=}& \mathbf{16.3^{\circ}} \\\\ \hline \end{array}$$

Dec 6, 2017