Is it possible to modify a polygon anywhere other than at the corner vertices?

The correct answer reflects the fundamental principle of how polygons are structured in GIS applications. Generally, polygons are defined by their corner vertices, and any manipulation or modification typically relies on adjusting these points. In many GIS environments, including Esri ArcGIS Pro, the basic editing functions focus on moving or redefining corner vertices to resize or reshape the polygon.

While advanced techniques or specific tools might allow for more complex alterations, standard polygon editing does not support modifications away from these vertices in a straightforward way. This means that to achieve a direct modification of a polygon, one would primarily work at the corner vertices to either resize or reposition the shape accurately.

This foundational understanding of polygons assists in grasping more complex editing tools and techniques that may be discussed later, especially as one becomes more familiar with advanced functionalities within Esri's software.