Answer:
The correct options are;
1. Definition of supplementary angles
2. m∠1 + m∠2 = m∠1 + m∠3
3. m∠2 = m∠3
4. Definition of Congruent Angles
Explanation:
The two column proof is presented as follows;
Statement
Reason
1. ∠1 and ∠2 are supplementary
Given
∠1 and ∠3 are supplementary
2. m∠1 + m∠2 = 180°
Definition of supplementary angles
m∠1 + m∠3 = 180°
3. m∠1 + m∠2 = m∠1 + m∠3
Transitive Property
4. m∠2 = m∠3
Subtraction Property of Equality
5. ∠2 ≅ ∠3
Definition of Congruent Angles
Given that angles ∠1 and ∠2 are supplementary angles and angles ∠1 and ∠3 are are also supplementary angles, then the sums of m∠1 + m∠2 and m∠1 + m∠3 are equal, therefore, ∠2 and ∠3 have equal quantitative value and therefore ∠2 = ∠3 and by definition, ∠2 ≅ ∠3.