The refractive index law is expressed as sin(i)/sin(r), but the interpretation of angles i and r can vary based on the medium. The equation can also be represented as sin(α) n_α = sin(β) n_β, where n represents the refractive index of each medium. In the discussed scenario, the angle i corresponds to the light entering water, while angle r relates to the light exiting into air. Consistency in labeling angles is crucial for accurate application of the law. Understanding the context of each medium's refractive index clarifies the relationship between the angles.