Answer:
x = 120°
Step-by-step explanation:
this is a 7-sided polygon and the sum of the interior angles is (7-2)×180° = 900°
add all 7 angles together and set equal to 900
x + 150 + x - 20 + 140 + 120 + x + 20 + 130 = 900
combine 'like terms'
3x + 540 = 900
3x = 360
x = 120
