Concept

Line: travels in both directions without end.

Line segment: part of a line that has a start point and an endpoint.

Ray: part of a line with a start point but no endpoint (it continues to travel in one direction).

Rule

To decide if a figure is a line, a line segment, or a ray:

1.  If the figure has a line with arrows pointing in both directions, this is a line.

2.  If the figure has a line that starts at one dot and ends at another dot, this is a line segment. 

3.  If the figure has a line with only one arrow pointing in one direction, this is a ray.

Example

Identify the figure.

Solution

This is a ray, because it has a line with only one arrow pointing in one direction.

Pre-requisite Skills

Identify Three Dimensional Figures (4.8.1)

Faces, Edges, and Vertices (4.8.2)

Nets of 3 Dimensional Figures (4.8.3)

Simple Polygons (4.9.1)