fine the value of x in this screenshot

Answer:
x = 125º
Step-by-step explanation:
Angles in a triangle add to 180º so:
180 - 42 - 83 = 180 - 125 = 55º
Angles on a straight line also add to 180º so to find x:
180 - 55 = 125º
x = 125º
Hope this helps.
The exterior angle theorem states that one exterior angle of a triangle will always be equal to the sum of the two opposite interior angles.
x is an exterior angle of the triangle.
We are given two interior angles in the triangle. These are opposite of x.
According to the exterior angle theorem, we can solve for x by adding these two angles:
x = 125