## Algebra and Trigonometry 10th Edition

$\phi = 111.80^{o}$ $\theta = 68.20$ d = 13.86
The following are the given values: a = 10 b = 14 c = 20 Using the Law of Cosines, we can find $\phi$: $cos(\phi) = \frac{10^{2} + 14^{2} - 20^{2}}{2(10)(14)}$ $\phi = 111.80^{o}$ Knowing that a parallelogram has $360^{o}$, we can find $\theta$: $\frac{360 - (111.80)(2)}{2} = 68.20$ $\theta = 68.20$ Using the Law of Cosines, we can find d: $d^{2} = 10^{2} + 14^{2} - 2(10)(14)cos(68.20^{o})$ d = 13.86 $\phi = 111.80^{o}$ $\theta = 68.20$ d = 13.86