Creating a new space shape

[Jennifer]

How difficult would it be to create a new space shape having these properties:

1. It would start out as a rectangle of some appropriate size, but would allow new handles to be created which could then be used to change the shape. These handles would behave like the handles on a closed shape created with the line tool.

2. The shape would display both the area and the perimeter in the appropriate units.

3. Bonus: There would be a way to create cutouts inside the shape and these would be subtracted from the area, but not from the perimeter.

Thanks