Here is the completed two-column proof with the statements and reasons filled in appropriately:
-
Statement: \( a \parallel b \) and \( e \parallel f \)
Reason: Given -
Statement: \( m \angle 5 + m \angle 7 = 180^\circ \) and \( m \angle 13 + m \angle 14 = 180^\circ \)
Reason: Corresponding Angles Theorem -
Statement: \( m \angle 5 + m \angle 6 = 180^\circ \) and \( m \angle 9 + m \angle 11 = 180^\circ \)
Reason: Definition of Linear Pair -
Statement: \( m \angle 13 + m \angle 6 = 180^\circ \) and \( m \angle 13 + m \angle 11 = 180^\circ \)
Reason: Substitution Property of Equality -
Statement: \( m \angle 13 + m \angle 6 = m \angle 13 + m \angle 11 \)
Reason: Transitive Property of Equality -
Statement: \( m \angle 6 = m \angle 11 \)
Reason: CPCTC Theorem
The proof shows that angles 6 and 11 are congruent by establishing relationships between the angles formed by parallel lines and a transversal, leading to the conclusion through properties of equality.