Bisecting a line

          In Geometry, Bisecting a line is cutting a line exactly in half. It may also be referred to as constructing a perpendicular bisector as the line you are drawing will be at a right angle to the original line. A line that passes through the mid point of the line segment is known as the segment Bisector.

Problem: To bisect a given straight line AB

1. Draw a straight line of given dimension and mark start and end points as A, B.

2.  To bisect this line, set your compass to just more than half the length of the line. Keep your compass this size for the rest of the question.

3. Place compass on one end of the line (i.e., point B) and draw an arc that crosses the line AB. Do not adjust the compass and keep the same length.

4. Place compass on the other end of the line (i.e., point A) and draw an arc. It must cut the other arc above and below the line. Mark the point of intersections as C,D.

5. Draw a straight line through where the two arcs intersect above and below the line (i.e., C,D). It will cut the line AB at O. CD bisects AB at right angles. 

6. Measure both sides of the line from 'O' check that they are of equal length, if they are equal we did it correctly.