Answer:
55°
Step-by-step explanation:
The corresponding image, which I will attach, is missing in order to solve the exercise.
We know that the flat angle is 180 °, which we know to be the one that is formed with the horizontal, therefore the following equation remains:
55 ° + (70 ° + x °) = 180 °
we solve x °
x ° = 180 ° - 55 ° - 70 °
x ° = 55 °
So the value of x is 55 °