Answer:
71 degrees !!
Explanation:
Since the angles A and B both are next to each other, they form a linear pair. Since they are a linear pair, they both add up to 180 degrees (same as a straight angle!) So, if A is 109, you would simply subtract that from 180, and you'd get 71 !!
180-109= 71 !!
I hope this helps... have a great day !