Which term describes naming a line segment by its endpoints such as AB?

• A. Line
• B. Line segment
• C. Ray
• D. Point

Answer: (B)

Naming a line segment by its endpoints describes the part of a line that has two endpoints. When you see something like AB, think of the piece of a line that starts at point A and ends at point B. That bounded piece is what we call a line segment. It’s different from a line, which goes on forever in both directions; and different from a ray, which starts at a point and goes off in one direction. It’s also not just a point, which is simply a location with no length. So AB naming the segment from A to B points to the finite piece between those two endpoints, which is exactly a line segment.