Answer
Statements:
2. $\angle$2≅$\angle$3
3. $\angle$1≅$\angle$2
Reasons:
1. Given
4. The sides across from the base angles of an isosceles triangle are congruent.
Work Step by Step
Statement 1 is given and statement 2 is true because of the definition of vertical angles. Statement 3 confirms that ABC is an isosceles triangle therefore statement 4 is proven.