Answer: Substitution Property and Transitive Property
Explanation:
If ∠1 ≅ ∠2 and ∠2 ≅ ∠3 the two reasons that allow you to conclude that ∠1 ≅ ∠3 are the substitution property and the transitive property. The substitution property states that, if two geometric objects are congruent, you can substitute one for the other in a statement. The transitive property states that, if two geometric objects are congruent to another geometric object, then the two objects themselves are congruent.