The Solution:
Given:
Required:
To construct a bisector of each of the given lines.
Steps:
1. Take your compass and put the pin on one end of the line, and then expand the compass to at least more than half the length of the line ( but not greater than the length of the line).
2. Make an arc on the upper side and the lower side of the middle of the line, and then repeat the process when you take the pin mouth of the compass to the other end of the given line.
3. Connect the pairs of intersections of the arcs to make a straight line.
The straight is the required bisector.
Below is an example with the first line:
