All the steps I added have red numbers. The things I changed are in red as well.

Statements:

1. ;

2. ;

3.

4.

5.

6.

Reasoning:

1. Given

2. Angle addition postulate

3. Transitive property (or Substitution)

4. Transitive Property (or Substitution)

5. Substitution

6. Subtraction property of equality