Answer
$sin~120°=\frac{\sqrt 3}{2}$
$cos~120°=-\frac{1}{2}$
$tan~120°=-\sqrt 3$
Work Step by Step
Let $θ'$ be the reference angle. We must have that $0°\leqθ'\lt360°$
But, since $0°\leqθ=120°\lt360°$, it is not necessary to find the reference angle.
$sin~120°=\frac{\sqrt 3}{2}$
$cos~120°=-\frac{1}{2}$
$tan~120°=-\sqrt 3$
