Supplements
of Congruent Angles are Congruent
1. / 1 = / 2. 1. Given.
2. / 3 is supplementary to / 1. 2. Given.
3. / 4 is supplementary to / 2. 3. Given
4. / 3 + / 1 = 180. 4. Definition of supplementary.
5. / 4 + / 2 = 180. 5. Definition of supplementary.
6. / 3 + / 1 = / 4 + / 2 6. Substitution property.
7. / 3 + / 1 = / 4 + / 1 7. Substitution property.
8. / 3 = / 4 8. Subtraction property.