Answer:
50
Explanation:
Angle 1 is inside a triangle. Angles in a triangle add up to 180.
Angle 1 = 180 - 90 - 40 = 50.
Angle 2 is on a straight line (180 degrees), shared with angle 1. Therefore, angle 2 is 180 - Angle 1 = 130. Angle 3 and 4 can be calculated the same way Angle 2 was calculated (1=3, 2=4).
Angle 5 is 180 - 90 - Angle 3 which is 180-90-50 which is 40.
Angle 6 is 180 - Angle 5 = 180 - 40 = 140.
Angle 8 is the same as Angle 6
Finally, Angle 7 is 180-90 = 90.
Hope that helped!