Here's how to complete the two-column proof with the appropriate statements and reasons:
Statements:
- a ∥ b and e ∥ f
- m∠5 + m∠6 = 180° and m∠9 + m∠11 = 180°
- m∠13 + m∠6 = 180° and m∠13 + m∠11 = 180°
- m∠6 = m∠11
Reasons:
- given
- definition of linear pair
- corresponding angles theorem
- Transitive Property of Equality
So the completed proof looks like this:
| Statement | Reason | |-----------------------------------------------------|------------------------------------| | 1. a ∥ b and e ∥ f | given | | 2. m∠5 + m∠6 = 180° and m∠9 + m∠11 = 180° | definition of linear pair | | 3. m∠13 + m∠6 = 180° and m∠13 + m∠11 = 180° | corresponding angles theorem | | 4. m∠6 = m∠11 | Transitive Property of Equality |
This arrangement proves that angles ∠6 and ∠11 are congruent in the parallelogram.