Key idea we talked about after the warm-up up was the similarities and differences between Similarity and Congruence; specifically:
Congruent shapes have congruent angles and congruent sides.
Similar shapes have congruent angles but proportional sides.
Although the definition of each talks about all corresponding parts, thinking back to last semester’s triangle congruence criteria, there were “shortcuts” that allowed us to use only 3 pairs of congruent corresponding parts in a certain structure (SSS, SAS, ASA, AAS). It is a similar situation for triangle similarity. We won’t need to know that all three pairs of corresponding sides are proportional and that all three pairs of corresponding angles are congruent, there will be “shortcuts,” which will be discovered and articulated in the task on p. 257-260. See below for some hints for completing the task, and which problems to skip (1c, 4a-f, 6c-e).