Daniel is constructing a fence that consists of parallel sides line AB and line EF. Complete the proof to explain how he can show that m∠GKB = 120° by filling in the missing justifications. Statement Justification line AB ∥ line EF m∠ELJ = 120° Given m∠ELJ + m∠ELK = 180° Linear Pair Postulate m∠BKL + m∠GKB = 180° Linear Pair Postulate m∠ELJ + m∠ELK = m∠BKL + m∠GKB Transitive Property ∠ELK ≅ ∠BKL 1. m∠ELK = m∠BKL 2. m∠ELJ + m∠ELK = m∠ELK + m∠GKB Substitution Property m∠ELJ = m∠GKB Subtraction Property m∠GKB = m∠ELJ Symmetric Property m∠GKB = 120° Substitution