An airplane flies 200 km due west from city A to city B and then 320 km in the direction of 25.0° north of west from city B to city C.

(a) In straight-line distance, how far is city C from city A? _____km

(b) Relative to city A, in what direction is city C? _______° north of west

Vector (spatial) - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Vector_addition#Vector_addition_and_subtraction)

skcooky disagrees: It didn't help me with my problem

Well it should have, because it asnwers your question directly.