Answer:
Displacement is a straight line from the starting point to the finish point 
 blocks in North-West direction.
 blocks in North-West direction.
Explanation:
The figure below shows the movement of person and standard direction taken. 
AB represents the movement of person 6 blocks towards north and BC represents the movement of person 6 blocks towards west. A to C defines the distance traveled by the person.
Displacement is defined as the shortest distance covered between two points.
Here, displacement is the distance between point A and C.
Since, angle at B is right angle So, ΔABC is a right angled triangle.
Pythagoras theorem states that in a right angled triangle sum of square of base and perpendicular is equal to the square of hypotenuse.  
Applying Pythagoras theorem in ΔABC, we get 





 Thus, displacement is a straight line from the starting point to the finish point 
 blocks in North-West direction.
 blocks in North-West direction.