# Definition:Line/Straight Line Segment

## Definition

A **straight line segment** is a line segment which is straight.

In the words of Euclid:

*A straight line segment can be drawn joining any two points.*

(*The Elements*: Postulates: Euclid's Second Postulate)

Thus a definition for **straight line** which is frequently encountered is:

This is all very well but it assumes that the line in question terminates at two particular endpoints.