Surveying is the process of measuring the characteristics of the land upon which a construction work is supposed to take place. One of the most common ways to do surveys is to use chain surveying. In this method, we can use special pins, called ?arrows? for marking purposes.
Arrows are often used in surveying large flats of lands. In this situation, the measuring chain length is often shorter than the stretch of land that has to be measured. Then, a pin is stuck in the ground to mark the ends of the chain, and at the end, the pins are counted, and knowing the length of the chain beforehand, we can find out the length measured in this way.