This unit focuses on triangle congruency, specifically the methods of proving that two triangles are congruent using various postulates: Side-Side-Side (SSS), Side-Angle-Side (SAS), Angle-Side-Angle (ASA), and Angle-Angle-Side (AAS). Each method provides a unique way of establishing congruence based on the relationship of sides and angles in triangles. The section includes definitions, examples, and questions that prompt students to apply these concepts to determine congruence in various scenarios. Students will learn to recognize which congruence criteria to use in different situations and how to articulate their reasoning for triangle congruency statements.