Honors Geometry Lesson 8.5 Proving that Triangles are Similar What You Should Learn Why You Should Learn It How to use the SSS and SAS Similarity Theorems to prove that two triangles are similar How to use similar triangles to solve real-life problems You can use similar triangles to solve real-life problems such as understanding how a pantograph can be used to enlarge a figure Ways to Prove that Triangles are Similar Definition of similar triangles AA Similarity Postulate Side-Side-Side (SSS) Similarity Theorem Side-Angle-Side (SAS) Similarity Theorem Theorem 8.2 Side-Side-Side (SSS) Similarity Theorem If corresponding sides of two triangles are proportional, then the two triangles are similar Proof of SSS Similarity Theorem S T R M L N P Q