Calculating an angle using Snell's Law (refraction of light). Physico-Chemistry Methodology

How to calculate an angle using the Law of Refraction of Light? Example here with an exercise taken from the full video on my YouTube channel. High school - 10th grade level. --- 🧪 All videos categorized by topic and level, all links to social media: https://physicochimicomethodo.fr/ 🧪 To subscribe:    / @physicochimicomethodo   Jmbé Media - PCM 2025