# Unit 2: Module 2: Similarity, proof, and trigonometry

## About this unit

"Just as rigid motions are used to define congruence in Module 1, so dilations are added to define similarity in Module 2. To be able to discuss similarity, students must first have a clear understanding of how dilations behave. This is done in two parts, by studying how dilations yield scale drawings and reasoning why the properties of dilations must be true. Once dilations are clearly established, similarity transformations are defined and length and angle relationships are examined, yielding triangle similarity criteria. An in-depth look at similarity within right triangles follows, and finally the module ends with a study of right triangle trigonometry." Eureka Math/EngageNY (c) 2015 GreatMinds.org

### Learn

### Practice

- Dilate pointsGet 3 of 4 questions to level up!
- Dilations: scale factorGet 3 of 4 questions to level up!
- Dilations: centerGet 3 of 4 questions to level up!
- Dilate trianglesGet 3 of 4 questions to level up!
- Dilations and propertiesGet 3 of 4 questions to level up!

### Practice

- Similarity & transformationsGet 3 of 4 questions to level up!
- Sequences of transformationsGet 3 of 4 questions to level up!

### Learn

### Practice

- Determine similar triangles: AnglesGet 3 of 4 questions to level up!
- Determine similar triangles: SSSGet 3 of 4 questions to level up!
- Solve similar triangles (basic)Get 3 of 4 questions to level up!
- Solve similar triangles (advanced)Get 3 of 4 questions to level up!

### Learn

### Practice

- Solve triangles: angle bisector theoremGet 3 of 4 questions to level up!
- Use similar trianglesGet 3 of 4 questions to level up!

### Learn

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- Simplify square rootsGet 3 of 4 questions to level up!
- Simplify square roots (variables)Get 3 of 4 questions to level up!
- Simplify square-root expressionsGet 3 of 4 questions to level up!

### Learn

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- Trigonometric ratios in right trianglesGet 3 of 4 questions to level up!
- Solve for a side in right trianglesGet 3 of 4 questions to level up!

### Learn

### Practice

- Special right trianglesGet 3 of 4 questions to level up!

### Practice

- Solve for an angle in right trianglesGet 3 of 4 questions to level up!

### Practice

- Right triangle trigonometry word problemsGet 3 of 4 questions to level up!

### Learn

### Practice

- Solve triangles using the law of sinesGet 3 of 4 questions to level up!
- Solve triangles using the law of cosinesGet 3 of 4 questions to level up!
- General triangle word problemsGet 3 of 4 questions to level up!