Answer:
18. 150
19. They are not congruent
20. 60
Step-by-step explanation:
18. <EBC is 180 degrees so subtract by 30 because of angle F lowering the degree number by 30 and you get 150 degrees.
19. They are not congruent because they are not the same degree number and they aren't complementary because they don't equal 90 degrees. They aren't supplementary because they don't equal 180 degrees.
20. You get this by writing the equation 90-30 because angle F raises which lowers the angle dregree number by 30. So 90-30=60. Therefore, the answer is 60.
