1. The document discusses triangle similarity and the different postulates and theorems used to prove triangles are similar, including AA similarity, SSS similarity, and SAS similarity. 2. Examples are provided to demonstrate using these rules to verify similarity between triangles and find missing side lengths in similar triangles using proportional reasoning. Proofs of triangle similarity are also presented. 3. Applications of triangle similarity include finding dimensions in similar right triangles that model roof designs and solving other geometric problems.