Solve this ridiculous question i can't seem to answer

1. vertical angles are congruentso < n = 90

25 + 90 + 40 + m = 180
155 + m = 180
m = 180 - 155
m = 25

so < n = 90 and < m = 25

2. 50 + 90 + n = 180
     140 + n = 180
     n = 180 - 140
     n = 40

50 + 90 + m = 180
140 + m = 180
m = 180 - 140
m = 40

so < m and < n = 40

3. 50 + 40 + 52 + m = 180
     142 + m = 180
      m = 180 - 142
      m = 38

40 + 52 + 38 + n = 180
130 + n = 180
n = 180 - 130
n = 50

so < m = 38 and < n = 50
      

Iam confused on this my self