
How to construct a line perpendicular to a given line, and dividing it into two equal parts?

1. 
 Start with two points defining the given line.


2. 
 Draw an arc with its center in the point on the right, passing through the point on the left, and therefore with a radius equal to line 1.


3. 
 Repeat this for the points exchanged. Both arcs must intersect twice.


4. 
 Draw the connecting line between both intersections of arcs 2 and 3.


5. 
 This line is the perpendicular bisector of line 1. It is perpendicular to line 1 and divides it into two equal parts.

