A line segment is a fixed portion of a line. This makes it possible to measure a line segment.

**Example:**

Measuring line segments can be done by:

1) Comparing by observation.

Just by looking at them we can tell which one is longer.

2) Comparison by Tracing.

To compare AB and CD, we use a tracing paper, trace CD and place the traced segment on AB.

3) Comparison using ruler and divider.

Use the ruler, mark the measurements and compare the value.