The class was started by solving a few physics mathematical problems which reinforced the solving for unknowns and the importance of the use of units. A discussion of the differences between a fact, a hypothesis, a law or principle, and a theory was outlined with some examples and demonstrations of each. Reflection from a plane mirror was demonstrated with a laser and mirror, the rays identified and the angles formed by the incident ray and the reflected ray were shown to be equal, always. This was an example of a law. A series of statements was outlined, and Abby was asked to determine if they were a hypothesis?