Question

This diagram was created by starting with points A and

B and using only straightedge and compass to construct
the rest. All steps of the construction are visible.
Describe precisely the straightedge and compass moves
required to construct the line CD in this diagram.

Answer 1

Move 1: Place the compass at point A and draw circle A with center at A and radius AB

Move 2: Place the compass at any point of the circumference of circle A and label the point, at point B. Draw a second circle with the same radius AB and center at point B with the compass

Move 3: Label the point the two circles intersect as points C and D

Move 4: Place the straightedge at points C and D and construct the straight line CD

Explanation: