What two borders of a township are affected by the curvature of the earth and measurement errors?

The correct choice highlights that the north and south borders of a township are affected by the curvature of the Earth and related measurement errors. This phenomenon occurs because townships are generally delineated using a grid system based on a rectangular survey method, where the meridians (lines of longitude) converge at the poles.

As one moves further from the poles toward the equator, the distance between lines of latitude (which run east and west) remains somewhat constant, but the north-south lines (meridians) approach each other. This convergence can create discrepancies in the measurement of land area and straight-line distances if the curvature of the Earth is not accounted for.

In contrast, east and west measurements across townships maintain relatively consistent spacing since lines of latitude remain parallel; therefore, any measurement errors or curvature effects are not as pronounced in these directions compared to the north and south. Understanding this aspect of land surveying is crucial for accurate assessments and property delineation in accordance with the grid system utilized in Wisconsin and across the United States.