A method of establishing a geodetic control surveys consisting of connected triangles or polygons where all _____ are measured is called _____

• A. lengths, trilateration
• B. angles, traverse
• C. lengths, traverse
• D. angles, trilateration

Answer: (A)

The idea being tested is the difference between trilateration and triangulation in a geodetic network. When a network is built from connected triangles or polygons and every side length is measured, positions are determined by distances to known points. Those distances define circles around the reference points, and the intersections of these circles fix the unknown locations—the essence of trilateration. If you instead measured angles to define the geometry of the network, you’d be using triangulation, which relies on angular relationships rather than full distance measurements. So the correct approach is measuring lengths to apply trilateration, since it specifies determining positions from all side lengths in the network. The other options mix angle measurements with methods that aren’t defined by a network of fully measured sides, so they don’t fit this description.