Answer: The sailboat is at a distance of 15 km from the port.
Step-by-step explanation: Given that a sail boat leaves port and sails 12 kilometers west and then 9 kilometers north.
We are to find the distance between the sailboat from the port in kilometers.
Since the directions west and north are at right-angles, we can visualize the movement of the sailboat in the form of a right-angled triangle as shown in the attached figure.
The sailboat moves leaves the port at P and reach O after sailing 12 km west. From point O, again it moves towards north 9 km and reach the point S.
PS = ?
Using the Pythagoras theorem, we have from right-angled triangle SOP,
Thus, the sailboat is at a distance of 15 km from the port.
