What part of the Datum Identification Symbol connects to the triangle?

In the context of GD&T, the Datum Identification Symbol consists of different components that serve specific purposes in defining a datum. The part of the Datum Identification Symbol that connects to the triangle is the stem. The stem extends from the box, which contains a letter designating the datum feature, and it connects to the triangle that indicates the type of datum being referenced.

This connection is essential because it visually establishes the relationship between the datum feature and the triangle, which may signify either primary, secondary, or tertiary datums based on its position. Understanding this structure is crucial for properly interpreting engineering drawings and ensuring accurate manufacturing and inspection processes.