Describe a process you would use to create the perpendicular bisector to a segment AB using only an unmarked straig and an unmarked compass.

1 answer

To create the perpendicular bisector of segment AB using only an unmarked straightedge and an unmarked compass, you can follow these steps:

1. Begin with segment AB, and mark points C and D on the segment to divide it into two equal parts. These points will be used later for constructing the perpendicular bisector.

2. Place the compass on point C (or D) and draw an arc that intersects the segment AB on both sides. Keep the compass width consistent throughout the process.

3. Without changing the compass width, place the compass on point D (or C) and draw a similar arc that also intersects the segment AB on both sides. The two arcs should intersect, creating two additional points of intersection - E and F - respectively.

4. Use the straightedge to draw a straight line connecting points E and F. This line will serve as the perpendicular bisector.

5. To confirm that the line EF is a perpendicular bisector, use the compass to measure the distance between points A and F (or E). Without changing the compass width, place the compass on point B and draw an arc above and below the segment AB.

6. Keep the same widest compass width and place the compass on point A. Draw an arc that intersects the previous two arcs. Mark the point of intersection, labeled as G.

7. Use the straightedge to draw a line connecting point G and point B.

At this point, the line GB should intersect the line EF at a right angle, thus confirming that EF is the perpendicular bisector of segment AB.