In the proof that consecutive interior angles are supplementary, the missing reason in the proof where \( m∠A = m∠E \) (Statement 2) is related to the relationship between parallel lines and the angles that are formed when a transversal crosses them.
The correct reason to fill in for Statement 2 is: Corresponding Angles Postulate.
Thus the completed proof would look like this:
- \( m∠A + m∠C = 180° \) - Linear pairs are supplementary
- \( m∠A = m∠E \) - Corresponding Angles Postulate
- \( m∠E + m∠C = 180° \) - Substitution
- \( ∠E \) and \( ∠C \) are supplementary - Definition of supplementary angles
So the missing reason is Corresponding Angles Postulate.