___x____
\ |
\ |
\ | y
18 \ |
\ |
\ *|---2.2 °
This is a vector problem. The distance of drift is in x (horizontal axis).
remember that Sin Ф=opposite/hypotenuse. x represents the opposite side form the angle, and 18 is the hypotenuse.
Sin 2.2°=x/18
18 sin 2.2°=x
.691 ≈x
The ship drifts off course .691 miles every hour. .691 x 5 = 5.69 miles after 5 hours.