Final answer:
To construct a line through point X that is parallel to line r, use a compass and straightedge. Place the compass point on point X, adjust the width, draw arcs intersecting line r, and then draw a straight line through point X and the intersection points of the arcs.
Step-by-step explanation:
To construct a line through point X that is parallel to line r, you can use a compass and straightedge. First, place the compass point on point X and adjust the width to be greater than half the distance between point X and line r. Then, draw two arcs intersecting line r, making sure they are equidistant from point X on either side. Finally, draw a straight line through point X and the intersection points of the arcs, which will be parallel to line r.