Answer:
145°
Explanation:
[Finding the non-label angled in the triangle] 180° - 75° = 105°
Finding 3: (x = angle 3)
[Sum of a triangle's angles] 105° + 40° + x (angle 3) = 180
[combine like terms] 145° + x = 180°
[subtracting 145 from both sides] 35° = x
() We can test that this is correct by adding 40 and 35 together, to get angle 1 as it is an exterior angle
Finding 4: (x = angle 4)
180 - 35 = 145°
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather