It's SI unit is meters
The ISO length unit to use would be the cementer.
I would use inches.
I would use centimetres.
A meter.
The length of an aeroplane would be measured in metres.
miles or kilomiters
You would use the SI unit meter (m) to measure the length of a DVD case.
It would be normal to use either meters or feet, but you can use any unit for length (inches, cm, mm, km, etc.)
I would use feet
I would use feet.
Centimeters would be the best to use. ■
i would use inches