Answer
$-\sqrt 3$
Work Step by Step
The reference angle of an angle $0 \leq \theta \lt 2\pi $ based on its position can be computed by using the following steps:
a) Quadrant- I: $\theta $
b) Quadrant -II: $(\pi-\theta)$
c) Quadrant- III: $(\theta - \pi)$
d) Quadrant - IV: $(2\pi - \theta)$
We are in quadrant 2, so the reference angle of $180^{\circ}-120^{\circ}=60^{\circ}$
Thus, we have $ \tan 60^{\circ}=-\sqrt 3$
(because tangent is negative in quadrant 2.)
