A Geometric Approach to Fermat Principle as a Demonstration of High School Geometry and Physical Optics

Fermat's principle states that a light ray refracted across different media will traverse the fastest path as the physics for Snell's law. A geometric proof of Fermat's principle will be demonstrated as an intuitive approach to learn high school geometry and physical optics. It will be proved explicitly by showing that all alternative paths need more traversal time to complete their journey.