18. Supplementary angles add up to 180 degrees
-> W = 180 - 49 = 131 (degrees)
19. Because angle 1 and 2 are vertical, they're equal to each other.
We know that supplementary angles add up to 180 degress -> Angle 1 = 180 - 56 = 124 (degrees)
20. Label the measurement of angle 1 as x.
Since angle 1 is 18 degrees less than five times angle 2, angle 2 = 5(x+18)
Angles forming a linear pair are supplementary.
-> x + 5(x+18) = 180
-> 6x + 90 = 180
-> x = 15.
Hence, angle 1 = 15 degrees.