Final answer:
It is false that a surveyor can start at any benchmark for elevation measurements without referencing the city datum point, as benchmarks must relate to a common datum to ensure accuracy.
Step-by-step explanation:
The statement that a surveyor may begin at any benchmark to make necessary elevation measurements without having to refer to the city datum point is false. A benchmark is a reference point whose elevation is known relative to a standard datum, typically the national or local datum. When making elevation measurements, surveyors often need to refer back to a common source, such as the city datum, to ensure all measurements are consistent and accurate relative to that datum. Starting from an arbitrary benchmark without considering its relation to the city datum could lead to inaccurate or non-uniform elevation readings, compromising the survey's integrity.
Surveyors use various tools and methods, such as theodolites, to measure angles and distances. The principles of triangulation and baseline measurements form the basis for determining relative positions and topographies. The concept of parallax is also applied in surveying, indicating the apparent shift in an object's position due to a change in the observer's viewpoint.