The next method of corner restoration which will be considered is the three-point control method. The following section describes what it is, where it is used, and how it is computed.

Three-point control is used in situations where known corners exist in only three directions from a lost point. The fourth direction was never surveyed, so it is impossible to use an original corner for a proportionate four-way control in that direction.

In such a situation, Section 5-29 of the manual states: "Where the line has not been established in one direction from the missing corner, the record distance will be used to the nearest identified corner in the opposite direction."