Describing an area of a 2D array?

Okay so, lets say I have a randomly shaped area on a 2D array, and a “Room” class that holds that area. How can I describe this area through the room class? would it just be a 2D array? a list of coordinates?

If it can be arbitrarily shaped, the most straightforward approach would just be a list of coordinates.

If the areas can only be rectangularly shaped, then you could describe it with just 4 numbers: start x, start y, width, height.

Yeah i decided to just keep it simple and go with that.