Question

Complete the proof!!!

Answer 1

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

Step-by-step 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°     ${}$                      (1) Definition of supplementary angles

m∠1 + m∠3 = 180°

3. (2) m∠1 + m∠2 = m∠1 + m∠3      ${}$     Transitive Property

4. (3) m∠2 = m∠3     ${}$                            Subtraction property of equality

5. ∠2 ≅ ∠3     ${}$                                       (4) Definition of congruent angles

Given that angles ∠1 and ∠2 are supplementary, we have, ∠1 + ∠2 = 180°

Given that angles ∠1 and ∠3 are also supplementary, we also have, ∠1 + ∠3 = 180°

∴ ∠1 + ∠2 = 180° = ∠1 + ∠3

∠1 + ∠2 = ∠1 + ∠3

∠1 + ∠2 - ∠1 = ∠1 + ∠3 - ∠1

∴ ∠2 = ∠3

∴ ∠2 ≅ ∠3, by definition of congruent angles.