There are so many unit to measure in length.S.I unit of length is meter.
A gram, since that is NOT a unit of measure for length!
The metric unit of length is the 'meter'.
The answer depends on what characteristic the tool is used to measure.
The basic unit used to measure length is called metre.
The meter is the unit of length.
Class room can be measure in Meters easily :)
the meter is used to measure distance or length.
Centimeters should be used to measure the length of a fork.
A metric tape measure will do.