As is drawn in Fig. $37-4$, a ray of light in air strikes a glass plate $(n=1.50)$ at an incidence angle of $50^{\circ}$. Determine the angles of the reflected and transmitted rays.
The law of reflection applies to the reflected ray. Therefore, the angle of reflection is $50^{\circ}$, as shown.
For the refracted ray, $n_{i} \sin \theta_{i}=n_{t} \sin \theta_{t}$ becomes
$$
\sin \theta_{t}=\frac{n_{i}}{n_{t}} \sin \theta_{i}=\frac{1.0}{1.5} \sin 50^{\circ}=0.51
$$
from which it follows that $\theta_{t}=31^{\circ}$.