Answer:
We can construct the given segment by using the following steps:
Step 1: Adjust the compass width equal to the length of the segment AB.
Step 2: Draw another line that is greater than the twice of the segment AB in length.
Step 3 : Without changing the compass settings, draw an arc from end of the line on the line (this is equal to length AB)
Step 4 : Now again put the compass tip on the intersection of the arc drawn above, and make another arc on the line (this is also equal to length AB from the arc)
Now, we get a double line segment from the end of the line.
Its like AB + AB = 2AB.
You can see the attached figure to get a clear view of construction.