I added the diagram of the question.
Answer:
h = 60°
Step-by-step explanation:
We are given that lines k and l are parallel lines.
This means that angles 120° and h are supplementary angles.
This means that their measures add up to 180°
Therefore:
180° = 120° + h
h = 180° - 120°
h = 60°
Hope this helps :)