Enlargement 2 Positive Fractional SF (NJT)

What stays the [b]same[/b] and what [b]changes[/b] when you move [list] [*]the SF slider [*]the centre [*]the vertices A,B and C? [/list] Are there any points that do not move under this transformation?

[color=#0a971e]Created by N.Trubridge[/color]