John rows his canoe due east across a river at 5.5 miles per hour. if the river is flowing south at 4 miles per hour, find john's direction.

This is the concept of trigonometry, the direction of the John will be given by:

tan theta=opposite/adjacent

suppose:

a=theta

opposite=4 mph

adjacent=5.5 mph

tan a=4/5.5

a=tan^-1 (4/5.5)

a=36

therefore the boat canoe will be moving 36 degrees from East, his direction will be 126 degrees south east