Answer:
19. x = 66
20. x = 10
21. x = 9
Step-by-step explanation:
19. 133 and (x - 19) are supplementary angles, meaning that the sum of them is 180. So:
180 = 133 + (x - 19)
47 = (x - 19)
66 = x
20. the two angles are complementary, meaning that they add up to 90 degrees (as shown by the red square in the corner). So:
90 = 63 + (2x + 7)
27 = 2x + 7
20 = 2x
10 = x
21. the two angles are vertical angles, meaning that they equal each other. So:
59 = (6x + 5)
54 = 6x
x = 9
