Distance and direction of an objects change in position from starting point

An object changes position if it moves relative to a reference point. The change in position is determined by the distance and direction of an object's change in position from the starting point (displacement). Direction • Direction is the line, or path along which something is moving, pointing, or aiming.

Explanation:

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)