Final answer:
When a non-living area shares a wall with a living area, both measurements typically include the wall, and a tape measure is the appropriate tool to use with units in feet or meters.
Step-by-step explanation:
When measuring the length of a room, you need to decide which measurements to include. If a non-living area shares a wall with a living area, the typical practice is option 3) Both the measurement of the non-living area and the living area include the wall. This ensures that each space is accounted for in the floor plan without duplicating the thickness of shared walls.
To measure a room, you would likely use a tape measure, as it allows you to measure long distances accurately. When selecting a unit of measurement, consider that room dimensions are usually provided in feet or meters, which are practical units for the scale of room sizes.