Write a two-column proof.
Given m<4 =35, m<1= m<2 + m<4.
Prove m<3 = 70

Answer:
given m<4 = 35° and m<1 = m<2 + m<4
prove m<3 = 70°
Statements Reasons
m<4 = 35° given
m<1 = m<2 + m<4 given
m<2 = m<4 by the vertical angles theorem
35° = 35° substitution property of equality
m<2 + m<4 = m<1 angle addition postulate
35° + 35° = 70° substitution property of equality
m<3 = m<1 by the vertical angles theorem
m<3 = 70° substitution property of equality