The principal of a closed traversed is that?

The question is asking about the principal of a closed traverse. A traverse is a series of connected survey points that form a closed shape. The principal of a closed traverse refers to the method used to determine the directions and distances between these points.

Option A states that the compass is read at each point in turn and back bearings are taken as a check. Back bearings are the opposite direction to the original bearing. This means that after taking a forward bearing, the compass is turned 180 degrees to take the back bearing. However, this is not the principal of a closed traverse.

Option B states that the compass is read and forward bearings are taken. This means that only the forward bearings, or the original directions, are measured at each point. However, this is not the principal of a closed traverse.

Option C states that the compass is read at each point and plotted as a check. This means that the compass readings are recorded at each point and then plotted on a map or graph. This allows for a visual representation of the traverse and helps to check for errors. Option C is the correct answer because it describes the principal of a closed traverse.

Option D states that the compass is read at each point and turned back at each point. This option does not provide enough information to determine its validity as the principal of a closed traverse.

In summary, the principal of a closed traverse is that the compass is read at each point and plotted as a check. This allows for accurate determination of directions and distances between survey points.