posted by Sev .
A boat sails 251 km to the East and then 534 km to the North. What is the distance of the boat from its starting point?
Draw the two displacement vectors end to end. That will be like drawing the path on a map. Then draw the hypotenuse that connects the starting point of one with the end point of the other (the destination)
The distance from the starting point is the hypotenuse of that right triangle.