## Precalculus (6th Edition) Blitzer

Navigate $N 46^{\circ} W$
Using the law of cosines we can plug in the known information: $b^{2} = a^{2}+c^{2} - 2*a*c*cos\beta$ Since $a = 7, c=6$ and $b = 5$ we have: $25 = 49+36-84*cos\beta$ $25 = 85-84*cos\beta$ $cos\beta = 0.714$ $\beta \approx44^{\circ}$ Subtract $44^{\circ}$ from $90^{\circ}$ to get $46^{\circ}$.