Answer:

11-12

180 = 4x + 30 + x + 15

180 = 5x + 45

5x = 135

x = 27

4(27) + 30 = 138 deg

27 + 15 = 42 deg

13-14

45 = 3x + 9

3x = 36

x = 12

3(12) + 9 = 45 deg

15-16

98 = angle 2 (vertical angles are the same)

angle 1 = 180 - 98

angle 1 = 82

angle 2 = 98

17-18

angle 4 = 121 deg (alternate exterior angles are the same)

angle 3 = angle 4

angle 3 = 121 deg (vertical angles are the same)

19. angle 1 = 180 - 42 = 138

20. angle 3 = angle 1 = 138 (corresponding angles are the same)

21. angle 4 = angle 2 = 42 (corresponding angles are the same)

22. angle 5 = angle 1 = 138 (alternate exterior angles are the same)

23. angle 6 = angle 2 = 42 (alternate interior angles are the same)

24. angle 7 = angle 1 = 138 (vertical angles are the same)

25. angle 8 = angle 2 = 42 (vertical angles are the same)