In this activity we see how to use the sun as a tool for navigation. Mark the shadow made by an upright stick twice, at an interval of around 15 minutes. Join the two marks with a straight line and draw a second line perpendicular to this line. As the sun moves from east to eat in the sky, the shadow moves from west to east. Thus the first mark denotes west while the second mark denotes east and north and south can now be marked on the perpendicular line.