What is the definition of a directed line segment?

A directed line segment is best defined as a vector. In geometry and mathematics, a vector is a quantity that has both magnitude and direction. A directed line segment visually represents this concept, as it is depicted as a straight line with an endpoint that indicates direction.

For example, if you were to use a directed line segment to represent a journey from one location to another, the length of the segment would indicate how far you need to travel, while the direction of the arrow (often placed at one end of the segment) would specify the path you should take.

In contrast, the other options point towards different concepts. A point in a plane is simply a position with no size or dimension, while a scalar measurement refers to a quantity described only by its magnitude, lacking any directional component. Lastly, an angle describes the inclination between two lines or planes and does not encapsulate the idea of a directional distance from one point to another. Thus, understanding that a directed line segment encapsulates both distance and direction, aligns perfectly with the definition of a vector.