Answer:
7
Step-by-step explanation:
Step-by-step explanation:
AB//CD (Opposite sides of parallelogram are parallel)
Angle A + Angle B = 180 (Sum of interior angles=180)
179 + 3x - 20 = 180
3x - 20 = 180 - 179
3x - 20 = 1
3x = 1 + 20
3x = 21
x = 21/3
x = 7
