Answer:
1 = 50°, 2 = 130°, 3 = 50°, 4 = 130°, 5 = 40°, 6 = 140°, 7 = 90°, 8 = 140°
Explanation:
The sum of the angles of a triangle is 180°. A flat angle measures 180° as well.
Angle 1: 180 - 90 - 40 = 50°
Angle 2: 180 - 50 = 130°
Angle 3: 180 - 130 = 50°
Angle 4: 180 - 50 = 130°
Angle 5: 180 - 90 - 50 = 40°
Angle 6: 180 - 40 = 140°
Angle 7: 180 - 90 = 90°
Angle 8: 180 - 40 = 140°
It's a little complicated, but I hope this helps!