Warm Up Find the number of triangles in each diagram Find the number of triangles in each diagram

3.1 What are Congruent figures? Objective: Understand the concept of congruent figures and accurately identify the corresponding parts of figures.

Congruent figures: Same size, same shape All sides, angles, and points the same Match up the same

Ex.1: B Y A C X Z If ABC = XYZ then A = X, B = Y, C= Z andAB = XY, BC = YZ, CA = ZX Notice letters match up in order Would the statement ABC = YXZ be correct?

Definition: = all pairs of corresponding parts are =. Definition: = all pairs of corresponding parts are =. “implies” “If..., then...” “implies” “If..., then...” the statement is reversible the statement is reversible

In later chapters = polygons all pairs of corresponding parts are =. In later chapters = polygons all pairs of corresponding parts are =.

K I E I E T Ex. 2 Reflection ove KT: ITK = ETK IK = EK IT = ET KT = KT (all use the reflexive property) Name = Name = Sides KET is a reflection of KIT KET is a reflection of KIT IKT = EKT IKT = EKT KET = KIT KET = KIT Postulate: any segment or angle is congruent to itself (reflexive property) (reflexive property)