You would use the same units whether it was up or not. Centimetres seems the most sensible unit.
I would use feet
You would use the unit of measure called "kilograms" to measure the mass of an elephant.
Which unit would you use to measure the water in a full tub?
You would use meters.
You would typically use a unit of weight, such as grams or ounces, to measure a cherry.
You would use area. I would use the meter2. Okay
The Unit Used To Measure A Train Can Be Kilometer.
You would typically use the metric unit of centimeters to measure the growth of your hair.
One of length. I'd go for Metres and Centimetres but you could use Feet and/or Yards. Or declare a new unit of "Flagpole" which is exactly one flagpole long....
if i were you , i would use kg
You would use Volume.
to measure a small trashcan