Start on a coordinate plane at (0, 0). Draw an arrow in the direction 340° bearing. (That is 20 degrees west of due north.) Label it with length 450.
Now consider where that arrow ended as your new starting point. Mentally you can think of it as a new origin. Now draw a new arrow that has a bearing of 250°. (Since bearing is measured clockwise from due north, this will be sort of like 8 o'clock direction.) Make this arrow longer, and label its length 510.
Question is probably asking you how far you are from your starting point. You'll need to think about what the interior angle formed by your two arrows is, and use law of cosines. (In this particular problem, you might find another approach, because of the special interior angle.)