9 Components
Big Ideas
Formative Assessment Lesson
End of Unit Assessments
Unit Outline
Big Ideas
Formative Assessment Lesson
End of Unit Assessments
Unit 3:

# Similarity and Proof

Why are dilations important to understanding similarity?
4 weeks

Unit three is about understanding similarity through dilations (similarity transformations). Students will use their knowledge of similarity and congruence to build an understanding of similar and congruent triangles (a special case of similarity, 1:1 ratio). Proportional reasoning and dilation are essential to this understanding. Students will prove figures are similar and prove relationships of proportional measurements using triangle similarity and congruence criteria.

Essential Questions:

• Why are dilations important to understanding similarity?
• What relationships exist between the sides and angles of similar triangles?
• How do we use similarity to prove relationships between and within figures?
Printable Unit Plan
• Geometry Unit Plan for Unit 3
Resource:
Geometry Unit Plan for Unit 3

This is a printable version of the entire unit plan. You can make a copy of it and edit it or download and print it as needed.

### Unit Outline

9 Components

Every unit begins with an Initial Task and ends with a Balanced Assessment, both focusing on core mathematics of the unit. The core mathematics is developed through a series of resources around Big Ideas; as you move through the unit, keep students focused on how these ideas are connected and how they address mathematical problem solving. Before attempting the Balanced Assessment, students have an opportunity to synthesize their knowledge through a multi-day Formative Assessment Lesson and teacher-designed re-engagement lessons.