Answer:
He is 5.6 km away
Explanation:
he starts traveling away from base and is 8.3 km away to start with
then he turns west and travels 13.9 km away
what this mean is that you have to subtract the distance he turned from the distance he started off with
ex: 13.9 - 8.3 = 5.9
to get your answer of how far away he is from the base