The Scale (Mark) tool is very similar to the Scale tool except that it allows you to define your own center for scaling and the reference unit used to determine the magnitude of the scaling. First touch the path you wish to scale. You can then either press the “use center” button which will mark the center of the path as the pivot point for scaling (this is the same as the Scale tool) or you can press the “mark ref 1” which will set a different pivot point. In either case, you then need to mark a second point using the “mark ref 2” button to define the unit of scaling. This is the distance between the two points and defines Scale 1. Now simply drag your finger to scale. Here’s an example.
There is one other construction option that can be set before construction begins. On the Transformations tab there's a checkbox labeled "Create Copy"
If this is enabled, a copy of the path will be created. The original path will not be affect in any way.