Rotate Selection in Preview

I am doing something I thought would be pretty easy, but apparently I was wrong.

I am wanting to edit blueprints for my sister-in-law's new bathroom redesign. I have made selections to the PNG with my rectangle tool for the shower, sinks, toilette, doors, etc., etc.,

I simply want to rotate these selections (not the entire imagine) 90°.

Right clicking to rotate, does nothing. Right clicking isn't allowed.

When I try to go to tools-rotate left with the selection selected it flips the entire imagine with the selection along with it.

I tried selecting the image, copying it to the clipboard and THEN rotating the imagine to get it to line up. That too doesn't work as Preview clears clipboard every time I rotate the entire image.

Surely I cannot be the only person wanting to do this. I am running 10.11.6

Solution 1:

1. Copy the selection.
2. Open the selection in a new document.
3. Rotate the new document.
4. Select and copy the new document.
5. Paste the new document into the original.
6. Re-position.