Triangulation in sketching is described as which of the following?

• A. Measuring angular distances only
• B. Using three points to define a polygon
• C. A field technique for drawing freehand triangles
• D. Measuring From Two (2) Known Reference Points (Permanent Fixed Objects) to the Evidence, Forming an Imagery Triangle.

Answer: (D)

Triangulation in sketching uses two fixed reference points in the scene to locate the evidence by forming a triangle with the unknown point. You establish two permanent objects on the scene, measure the direction from each to the evidence (or the angle to the evidence) and then draw a line from each reference point along that direction. Where those two lines intersect is the position of the evidence. This method relies on two independent bearings to pinpoint a single location, which makes the location reproducible and more accurate than relying on a single measurement.

Why this description fits best: it explicitly describes using two known points and forming a triangle with the evidence point, which is the essence of triangulation. The other options describe aspects that aren’t how triangulation is used in sketching—measuring angular distances alone, defining a polygon with three points, or a freehand field technique for triangles—all of which don’t capture the two-reference-point fix that triangulation requires.