Answer: 1) <2 and <4 are vert. angles=given
2)lines m and n intersect at P=def. of vertical angles
3)<2 and <3 are a linear pair=def. of a linear pair
4)m<2 + m<3=180 = angles addition postulate
5)<3 and <4 are a linear pair =def. of a linear pair
6)m<3 + m<4=180 = angle addition postulate
7)m<2+m<3=m<3+m<4 = substitution property
8)m<2=m<4 = subtraction property
9)<2=<4 = definition of = angles
Step-by-step explanation: