Unit 3: Similarity and Proof

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. 

Time frame:
4 weeks
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?
Overall Unit Flow:
Initial Task Developmental Lessons Closure & Assessment
1 lesson 3 weeks (approximately 1 week per big idea) 1 week