Answer
$n_1 \sin\theta_1 = n_2 \sin\theta_2$, where angles $\theta$ are measured relative to the normal line.
Explanation
When moving into an optically denser medium ($n_2 > n_1$), light bends toward the normal line ($\theta_2 < \theta_1$).
Home / Library / CSAT (Suneung) essentials: original practice / Synthetic flashcard
State Snell's Law for light passing from medium 1 (refractive index $n_1$) into medium 2 (refractive index $n_2$).
Study flashcard from the deck CSAT (Suneung) essentials: original practice.