Final answer:
A line segment named CD is denoted by its end points, labeled as 'C' and 'D.' It is a fundamental element in geometry, representing the portion of a line between two distinct points.
Step-by-step explanation:
A line segment labeled CD can be written in symbols by simply using the endpoints of the line segment as the letters 'C' and 'D.' In geometry, a line segment is the part of a line that is bounded by two distinct end points, and contains every point on the line between its endpoints. This concept is fundamental in the study of geometry, which is a branch of mathematics dealing with shapes, sizes, and the properties of space.
Depending on how it's positioned in a coordinate system, a line segment can be characterized in various ways. For example, if the segment is diagonal, it could be described as having a positive or negative slope. If it is horizontal or vertical, it will either be parallel to the x-axis or y-axis, respectively. These properties help in understanding the orientation and relations of line segments within the coordinate plane or geometric figures.