Answer:
45
Step-by-step explanation:
Upon examining the graph, you can realize that angle 3x is the same as the angle directly to the left of 9x. Since that makes a straight line, we can realize that that sums up to 180. We call this a linear pair.
so you have:
3x+9x = 12x = 180
x = 15
A important concept to know here is vertical angles. Vertical angles occur when two lines intersect each other. The opposite angles formed at an intersection are congruent, which is why 1 is congruent to 3x.
Therefore, angle 1 is 45 degrees.
