Final answer:
Avery should set the compass to the radius of the desired arc to swing arcs above and below the diameter. Both points on a spinning CD go through the same angle of rotation, but the one farther out traces a greater arc length.
Step-by-step explanation:
The question pertains to constructing arcs with a compass in a geometric construction. When Avery swings the arcs above and below diameter db, the width to which the compass should be set is equal to the radius of the desired arc. In this context, both points on the CD - one near the center and one near the outer edge - will go through the same angle of rotation when the CD spins. However, the one near the outer edge will trace a greater arc length despite the equal angles due to the larger circumference at a greater distance from the center.