+26367 law of sines
\(\begin{array}{|rcll|} \hline \dfrac{AB}{\sin(49^\circ)} &=& \dfrac{18}{\sin\Big(180^\circ-(49^\circ+78^\circ)\Big)} \\\\ && \boxed{\text{Formula: }\ \sin(180^\circ-\theta) = \sin(\theta)} \\\\ \dfrac{AB}{\sin(49^\circ)} &=& \dfrac{18}{\sin(49^\circ+78^\circ)} \\\\ \dfrac{AB}{\sin(49^\circ)} &=& \dfrac{18}{\sin(127^\circ)} \\\\ AB &=& \dfrac{18\sin(49^\circ)}{\sin(127^\circ)} \\\\ AB &=& \dfrac{18*0.75470958022}{0.79863551005} \\\\ AB &=& \dfrac{13.5847724440}{0.79863551005} \\\\ AB &=& 17.0099779851 \\ \mathbf{ AB } &\approx& \mathbf{17.0\ \text{in}} \\ \hline \end{array}\)
