2. This is the start of the congruent triangle criteria. They are derived in trigonometry courses using the Law of Sines and the Law of Cosines, so one wonders if it might be easier to derive them analytically without having to use the traditional method of moving one triangle until it coincides with another using translations, rotations, and reflections, as we do here.

Return to text

Analytic Foundations of Geometry

Robert S. Wilson