Answer:
102 degrees below horizontal
Step-by-step explanation:
if the first angle is 78 degrees, the angle on the other side of the line is 102 degrees because a straight line is 180 degrees, and a box would have a total of 360 degrees in it
because the same line passes through both horizontal lines, the angle 3 is equal to the opposite angle to the 78
180-78 = 102
another way to look at it is that the 78 degrees is the same angle directly above angle 3 because the horizontal lines are parallel, and if it is 78 degrees, that makes the angle below it (angle 3) 102 degrees since a straight line must add to 180 degrees
