Draw a line m. Draw a line n which is parallel to line m at a distance of 4 cm from it.
Steps of construction : (1) Draw a line m. (2) Take two points A and B on the line m. (3) Draw perpendiculars to the line m at A and B. (4) On the perpendicular lines, take points P and Q at a distance of 4 cm from A and B respectively. (5) Draw a line n passing through the points P and Q. So, line n is the required line parallel to the line m at a distance of 4 cm away from it.