How to best implement Equals for custom types?

Question

Say for a Point2 class, and the following Equals:

public override bool Equals ( object obj )

public bool Equals ( Point2 obj )

This is the

Answer 1

Lie Daniel L said,

public override bool Equals(object obj) {
    Point2 point = obj as Point2; // Point2? if Point2 is a struct
    return point != null && this.Equals(point);
}

public bool Equals(Point2 point) {
    ...
}