Exercise 4 Page 379

A couple of things we can visualize using dynamic geometry software are lines, segments, and rays.

• A segment, $\overline{AB},$ consists of two endpoints and all points that lie between $A$ and $B.$
• A ray, $\overrightarrow{AB},$ consists of an endpoint $A$ and all points that lie on the same side of $A$ as $B.$
• A line, $\overleftrightarrow{AB},$ is represented by a line with two arrowheads. It extends in both directions without end.

Let's draw these using a geometry software program.