Why line segment is considered a defined term in geometry?

A line segment is considered a defined term in geometry because it is a specific part of a line that has a clear and precise definition. It is defined as the portion of a line that is bounded by two distinct endpoints, containing all the points between them. This definition allows for the clear communication and understanding of concepts related to distance, measurement, and geometric relationships. Unlike undefined terms, defined terms like line segments provide a foundation for building more complex geometric concepts.