Answer
$\color{blue}{\sin{5.4} \approx -0.8}$
Work Step by Step
To approximate the value of $\sin{5.4}$, look for the y-value of the point where the terminal side o the angle 5.4 radians crosses the unit circle.
Notice that for the given angle, the y-value of the point described above is around $-0.8$.
Thus,
$\color{blue}{\sin{5.4} \approx -0.8}$
