Answer
$\dfrac{\sqrt 3}{2}$
Work Step by Step
We are given that $f(\theta)=\sin \theta$ and $\theta=60^{\circ}$
We know form the unit circle that
$\sin (60^{\circ})=\sin (\dfrac{\pi}{3})=\dfrac{\sqrt 3}{2}$
Thus, we have: $f(\theta)=\sin (60^{\circ}) \\=\sin (\dfrac{\pi}{3}) \\=\dfrac{\sqrt 3}{2}$