Answer:
45°
Step-by-step explanation:
The angle 1 and 2 are formed by a transversal and two parallel lines. These angles are consecutive interior angles because they are inside the parallel lines. The consecutive interior angles are angles that sum 180 degrees, so we can write the following equation
∠1 + ∠2 = 180
If ∠1 = 135, we can calculate ∠2 as
∠2 = 180 - ∠1
∠2 = 180 - 135
∠2 = 45
Therefore, the answer is 45°