
Doug C. answered 01/15/25
Math Tutor with Reputation to make difficult concepts understandable
Looks like you have all the reasons except for the last statement. Without a diagram not easy to confirm they are all correct. But once you have proven two triangles congruent (stated in step 5), then you can use the fact that "corresponding parts of congruent triangles are congruent". This is usually abbreviated as CPCTC.