To answer your first question, the points that are equidistant from points \( A \) and \( B \) are indeed those that lie on the perpendicular bisector \( FG \) of segment \( AB \). Based on your notation, the following points are correct:
- Y - correct
- Z - correct
- F - correct
- G - correct
Since you also have points W, X, P, and S with "no response given", it appears that they may not be relevant or correct in this context.
As for your second question regarding the theorem that proves which points are equidistant from \( A \) and \( B \), the correct response is:
- Perpendicular Bisector Theorem
This theorem states that any point on the perpendicular bisector of a line segment is equidistant from the endpoints of that segment.