Answer:
1. Given.
2. Alternate Interior Angles Theorem.
3. m<2 + m<7 = 180 by definition of supplementary angles. By definition of congruent angles, m<2 = m<4 and m<5 = m<7, therefore m<4 + m<5 = 180 by substitution property of equality. By definition of supplementary angles, <4 is supplementary to <5.
4. Converse of Consecutive Angles Theorem.
