I remember being laughed at when I cut out coffee filters with a certain angle in order to plan how I would position motion capturing cameras to cover the room optimally. My manager liked the pragmatism though
What does that have to do with implementing a 2D model of a room with movable furniture?
How is paper not accessible? Do people not have note paper? What about junk mail? The last few pages of a book? You can make a scale ruler with any uniform markings.