Steps of construction:
1. Draw a line PQ.
2. Take any two points A and B on the line.
3. Construct ∠PBF = 90° and ∠QAE = 90°
4. With A as center and radius 5 cm cut AE at C.
5. With B as center and radius 5 cm cut BF at D.
6. Join CD and produce it on either side to get the required line parallel to AB and at a distance of 5 cm from it.