This document describes an experiment to study Brewster's angle and polarization of light by reflection. Brewster's angle is defined as the angle of incidence at which light with a particular polarization is perfectly transmitted through a boundary between two transparent materials, without any reflection. The experimental setup involves a laser, polarizer, photodetector, glass plate, and rotational mount. By measuring the intensity of reflected light at different angles of incidence, Brewster's angle for the glass-air interface can be determined as the angle with minimal reflection. Applications of Brewster's angle discussed include polarized sunglasses, camera lenses, windows, and microscopy.