# Construct A Line Segment

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More Lessons for Geometry
Math Worksheets
In this lesson, we will learn how to use a compass and a ruler

- to construct a line segment of a certain length.
- to copy a line segment.

## Construct a Line Segment

* Example**: *

Construct a line segment with length 6 cm.

Solution:

Step 1 : Use a ruler to draw a straight line that is slightly longer than 6 cm. Mark the starting point (*P*) near the beginning of the line.

Step 2 : Stretch the 2 arms of the compasses on the ruler until the distance between the sharp end and the pencil end is 6 cm apart.

Step 3 : Put the compasses on the line with the sharp end at point *P* and mark an arc on the line using the pencil end.

** Step 4:** Remove the compasses and mark the point where the arc meets the line as point *Q*.

* Note* : While it may be easier to construct the line segment by simply marking off 6 cm with a ruler, this technique of using compasses is essential for other construction lessons.

The following video shows how to construct a line segment of a given length, on a given ray.

## Copy a Line Segment

The following video shows how to copy a line segment using only a compass and straightedge.

Constructions with a Compass: Copying a line segment

You can use the Mathway widget below to practice Algebra or other math topics. Try the given examples, or type in your own problem. Then click "Answer" to check your answer.