27.2k views
2 votes
\Using the law of sine and cosine find the measure of AB given angle A is 55, angle B is 44 an side b is 68

User Mugetsu
by
6.3k points

1 Answer

6 votes
so.. .it'd be more or less like the picture below then


\bf \textit{Law of sines} \\ \quad \\ \cfrac{sin(\measuredangle A)}{a}=\cfrac{sin(\measuredangle B)}{b}=\cfrac{sin(\measuredangle C)}{c}\\\\ -----------------------------\\\\ \measuredangle C=180-A-B\implies \measuredangle C=180-55-44\implies \measuredangle C=81 \\\\\\ \cfrac{sin(\measuredangle B)}{b}=\cfrac{sin(\measuredangle C)}{c}\implies \cfrac{sin(44^o)}{68}=\cfrac{sin(81^o)}{c} \\\\\\ \overline{AB}=c=\cfrac{68\cdot sin(81^o)}{sin(44^o)}

now, the angles are in degrees, thus, make sure your calculator is in Degree mode when taking the sines
\Using the law of sine and cosine find the measure of AB given angle A is 55, angle-example-1
User Ilya Karpeev
by
7.1k points