Which is the least accurate method of measurement during sketching?

• A. Baseline measurement
• B. Transecting baseline
• C. Coordinate measurement
• D. Triangulation

Answer: (B)

Accuracy in sketching depends on how measurements are anchored to stable references. Baseline measurement uses a fixed, known distance as a reference, giving a strong, reliable anchor for scaling all other points. Triangulation fixes a location by intersecting lines or distances from two known points, which constrains position very well and tends to be precise when both observations are accurate. Coordinate measurement places each point on a grid, so with proper instruments you can achieve high precision. Transecting the baseline, by contrast, relies on perpendiculars from the baseline to locate points. Small errors in maintaining a true right angle or in the perpendicular measurements accumulate, and those errors grow with distance from the baseline, making distant points especially less accurate. Because of this amplification of error, transecting the baseline is the least accurate method among common sketching techniques.