Answer:
Step-by-step explanation:
Number of side = n = 7
Sum of interior angles of 'n' sided polygon = (n - 2) *180
  = (7 - 2)* 180
  = 5 * 180
   = 900
x + 150 + x -20 + 140 + 120 + x + 20 + 130 = 900
Combine like terms
x +x +x + 150 - 20 + 140 + 120 + 20 +130 = 900
3x + 540 = 900 Â Â {Subtract 540 from both sides}
      3x  = 900 - 540
      3x = 360    {Divide both sides by 3}
       x = 360/3
x = 120
 Interior angle           Exterior angle
∠A = 120                  180 - 120 = 60
∠B = 130                  180 - 130 = 50
∠C = 120 + 20 = 140         180 - 140 = 40
∠D = 120                  180 - 120 = 60
∠E =  140                  180 - 140 = 40
∠F = 120 - 20 = 100          180 -100  = 80
∠G = 150                   180 - 150 = 30