How do you bisect a line segment?


Investigation Steps

 Step 1 Close 

(1) Move the Points A and B. How does the construction change?

(2) What happens when the segment is larger than 7? Why does this happen? How could you "fix" this condition? You can Click on the browser's Refresh button to reset the construction.

(3) Make this construction using a Compass and Straight Edge.

(4) Make this construction using a software program.


 Step 2 Close 
    Given a line segment AB, find its midpoint.
  • This lets you draw any line through the midpoint therefore bisecting it!
  • Place the center on point A and adjust the radius such that the drawing point is clearly past the middle of AB.
  • Draw an arc above and below line segment AB.
  • Now place the center point on point B. THE RADIUS MUST BE THE SAME.
  • Draw an arc above and below line segment AB.
  • Align your straight edge along the intersection points of the arcs and lightly draw a line connecting them. This line will intersect AB at its midpoint.
  • You have bisected the line segment.