Is there a way to edit a ruler ("dimension") to the size I need it to be?

For walls for instance I can edit the wall and enter the length.
For dimensions, all I found was to drag it as long as I need it to be. But often it ends up showing 3 decimals, and since the text is in the middle, in case of a long dimension I cannot even zoom in far enough to fine-tune, because the text is no longer in my screen.

It would be nice if I could right click, modify, and enter the exact size.
Or if this is already possible and I just didn't find how to do it, I would appreciate some help.

I would need this to draw the perimeter of the property around the house.

Thanks!