Line ED is parallel to FB. Transversal GH crosses line ED at C and crosses line FB at A. The measure of angle ECG is 121 degrees. Greg is constructing a fence that consists of parallel sides line ED and line FB. Complete the proof to explain how he can show that m∠FAC = 121° by finding the missing justifications.

StatementJustification
line ED ∥ line FB
m∠ECG = 121°Given
m∠ECG + m∠ECA = 180°Linear Pair Postulate
m∠FAC + m∠ECA = 180°1.
m∠ECG + m∠ECA = m∠FAC + m∠ECATransitive Property
m∠ECG = m∠FACSubtraction Property
m∠FAC = m∠ECGSymmetric Property
m∠FAC = 121°2.
1. Corresponding Angles Theorem; 2. Definition of Supplementary Angles
1. Definition of Supplementary Angles; 2. Corresponding Angles Theorem
1. Same-Side Interior Angles Theorem; 2. Substitution Property
1. Substitution Property; 2. Same-Side Interior Angles Theorem