Answer
x$\approx$ 10.5
Work Step by Step
using theorem 11.4.3 Law of cosine
$x^{2}$ = $(8)^{2}$ + $(12)^{2}$ - 2*8*12*cos 60°
$x^{2}$ = 64+144 - 2*8*12 * $\frac{1}{2}$
$x^{2}$ = 208 -96
$x^{2}$ = 112
x = $\sqrt 112$
x = 4$\sqrt 7$ $\approx$ 10.5
x$\approx$ 10.5
