The distance is measured from the rear of the designated take-off area to the nearest landing mark in the pit. From the front of the take-off area to the nearest pit landing spot Take the measurement perpendicular to the take-off line or its extension. The tape's zero end is put where the athlete lands. The other end is marked with a unit length. For example, if the distance from the back of the take-off area to the nearest pit is 20 feet (6 m), then the triple jump distance is 20 feet (6 m). The rule is that the mark must be flat and free-standing. It cannot be part of the takeoff platform or track. A vertical obstruction such as a light standard can be used if it is not lower than 10 feet (3 m). If the obstruction is lower than 10 feet (3 m), then it is illegal for an athlete to clear it. They must skip over the obstruction. A legal mark must be within the viewing range of the judges' boxes. If not, they should be placed there so that they can be seen by the athletes. An auxiliary line is drawn at 12 feet 6 inches (3.9 m) from the edge of the block. An attempt below this line does not qualify for the event. To measure the distance accurately, have a friend hold up a marker at the desired point during the take-off.