How to Prove Triangles Similar: Angle Angle (AA) Similarity Theorem (3 proof examples)

In this video, you're going to learn how to prove triangles similar using the Angle Angle (AA) similarity theorem. We’ll walk through three complete proofs together, step-by-step, so you can master the tips, tricks, and techniques needed for your geometry class. Each of these examples is slightly different, covering: Parallel Lines & Transversals: Using alternate interior angles and vertical angles. Overlapping Triangles: Identifying corresponding angles and using the reflexive property. Perpendicular Lines: Working with right angles and the right angle congruence theorem. Remember, to prove two triangles are similar, you only need to show that two angles are congruent! Once you do that, the triangles are automatically similar, meaning their corresponding sides are proportional. Timestamps: 0:00 Intro to Angle Angle Similarity 0:59 Example 1: Parallel Lines & Vertical Angles 3:50 Example 2: Overlapping Triangles & Corresponding Angles 7:04 Channel Membership Invite 7:56 Example 3: Perpendicular Lines & Right Angles 8:30 How to Write a Similarity Statement If you're enjoying this video and want to go deeper into learning math with me, I encourage you to join the channel membership! At the "Additional Videos" level, you'll get access to nearly 400 videos, including full geometry courses, midterm and final exam reviews, and ACT/SAT prep. #geometry #maths #trianglesimilarity #highschoolmath #mariomathtutoring ➡️JOIN the channel as a CHANNEL MEMBER at the "ADDITIONAL VIDEOS" level to get access to my math video courses(Algebra 1, Algebra 2/College Algebra, Geometry, PreCalculus), midterm & final exam reviews, ACT and SAT prep videos and more! (Over 390+ videos)    / @mariosmathtutoring