Provide the reasons for statements 3 and 5 in the proof.
given: ∠1 and ∠2 form a linear pair; m∠2 = 100°
prove: m∠1 = 80°

reason #3. _ postulate
reason# 5 _ property of equality

What is the next step in the given proof? choose the most logical approach. a. statement: m 1 + m 2 + 2(m 3) = 180° reason: angle addition b. statement: m 1 + m 3 = m 2 + m 3 reason: transitive property of equality c. statement: m 1 = m 2 reason: subtraction property of equality d. statement: m 1 + m 2 = m 2 + m 3 reason: substitution property of equality e. statement: 2(m 1) = m 2 + m 3 reason: substitution property of equality