Use the compass and ruler to construct the perpendicular bisector of the line segment AB.

Sure, here are the steps to construct the perpendicular bisector of a line segment AB using a compass and ruler:

1. Draw a line segment AB using your ruler.

2. Open your compass to slightly more than half the length of the line segment AB.

3. Place the point of the compass at A and draw an arc above and below the line segment AB.

4. Without changing the compass width, place the point of the compass at B and draw another arc so that it intersects with the first arc above and below the line segment AB.

5. Draw a line through the two points where the arcs intersect. This line is the perpendicular bisector of the line segment AB. It should intersect the line segment AB at a 90-degree angle and divide it into two equal parts.

Remember to always use a sharp pencil for accuracy.