The ship A sails north at the rate of 14 mile per hour , it represent the opposite side of a triangle. Ship B start at the same point and move east at the rate of 18 miles per hour, it represent the adjacent side.
The other rate telling you how fast the distance between them are changing can be computed using the Pythagorean theorem, since the change in time is 1 hour. From 12 noon to 1 pm.
