You have a plenty of segments of the same length at your disposal.
Put a segment and put another to meet at their ends. Set the counterclockwise angle between two segments at 180/5 degrees. If you repeat this process, it ends after five steps (see the picture).
Then, you can see a regular pentagon inside your figure.
If you put the segments with an angle of 180/n degrees, which polygon will you see inside the resulting figure?