Final Answer:
The value of x for which line a is parallel to line b is 28°, thus the correct option is 3.
Explanation:
Lines are said to be parallel if they have equal slopes. The slope of a line is defined as the ratio of change in y-coordinate to the change in x-coordinate.
Therefore, to find the value of x for which line a is parallel to line b, the slopes of both the lines must be equal. The slope of line a can be calculated by finding the ratio of the change in y-coordinate, i.e. (34° - 6° = 28°) to the change in x-coordinate, i.e. (56° - 28° = 28°). Therefore, the slope of line a is equal to the slope of line b, which is 1. Thus, the value of x for which line a is parallel to line b is 28°.