usually heated square feet.
That means actual living area.
inches
Metre.
You would use millimeters (mm) to measure the thickness of a house key, as it is a small unit appropriate for measuring such dimensions.
kilo-newtons.
metres
I would use inches or centimeters, or millimeters to measure this.
square footage
A common house fly is a very small animal. In order to get an accurate measurement, you would have to use millimeters.
usually heated square feet. That means actual living area.
Lengths are measured in meters.
m
I would go with millimetres