A line normal to the plumb line at all points is known as ............

When the image formed by the objective is not situated in the plane of cross-hairs ............

A plumb line is ............

In reciprocal leveling, the error which is not completely eliminated, is due to ............

The vertical distance above or below the datum is called ............

Point of tangency is the ............

When the measured length is less than the actual length, the error is known as ............

Which of the following is not used in measuring perpendicular offsets?

A tie line in a chain surveying ............