3.1 What are congruent figures? Objective: After studying this lesson you will be able to understand the concept of congruent figures and accurately identify the corresponding parts of figures.

So, about congruent figures…. Still unsure about proofs? Be patient, you may find you gain some confidence as we work with triangles! What you learn about congruent triangles will help you understand the characteristics of other geometric figures. So, about congruent figures….

Congruent figures have the same size and shape. In general, two geometric figures are congruent if one of them could be placed one on top of the other and fit exactly, point for point, side for side and angle for angle.

Every triangle has 6 parts 3 sides 3 angles When we say that ABC FED we are saying: Congruent triangles all pairs of corresponding parts are congruent Remember that an arrow symbol means “implies” (“If …, then…”). If the arrow is double , the statement is reversible.

Name all of the congruent parts BOW I Definition: Congruent polygons all pairs of corresponding parts are congruent.

KET is a reflection of KIT over KT reflects onto 1 2 I E reflects onto reflects onto reflects onto 3 4 reflects onto reflects onto T by the reflexive property Postulate Any segment or angle is congruent to itself (reflexive property)

Summary: Draw two congruent figures and name all of the corresponding parts. Homework: worksheet