# Chapter 2

## Justification and Similarity

### Section 2.1

You will review triangle congruence conditions and angle relationships. You will write proofs using flowcharts and learn proof by contradiction.

• 2.1.1 Triangle Congruence Theorems (165)
• 2.1.2 Flowcharts for Congruence (175)
• 2.1.3 Converses (183)
• 2.1.4 Proof by Contradiction (192)

### Section 2.2

Through an exploration with rubber bands, you will investigate the dilation transformation and determine the common qualities of a figure and its image after a dilation. Then you will learn about the properties of similar figures.

• 2.2.1 Dilations (202)
• 2.2.2 Similarity (215)

### Section 2.3

You will discover the conditions that can be used to determine whether triangles are similar, and you will use flowcharts to organize facts and support your conclusions. You will solve both mathematical and everyday problems involving similar figures and deepen your understanding of proof.

• 2.3.1 Conditions for Triangle Similarity (225)
• 2.3.2 Determining Similar Triangles (242)
• 2.3.3 Applying Similarity (250)
• 2.3.4 Similar Triangle Proofs (259)