a. Given.
You were given the proof.
b. Corresponding angles are congruent.
Since angles 1 and 2 are corresponding, then if one is 130, then the other one is also 130.
c. Vertical angles are congruent.
Angles 2 and 3 are vertical, meaning they'll also be congruent.
d. Transitive Property of Equality.
If angles 2 and 3 are vertical, then if 2 is 130, then 3 is also 130.