Kilometers
Miles or kilometers.
Neither. The relevant standard unit is a kilometre.
Distances and vast lengths in the USA are measured in miles.
Kilometers
We can measure how long things are , how tall,or how far apaart they are .Those are examples of length meaasurements. The basic unit of length is meters.
A unit can be a measure of length. It is one-dimensional. A squared unit can be a measure of area. It is two-dimensional. A cubic unit can be a measure of volume. It is three-dimensional.
Kilometres or miles
the least unit to measure the length is fermo meter .
Kilometres are the appropriate unit.
The metric unit of length is the 'meter'.
I would typically use kilometers to measure the distance between Delhi and Mumbai, as it is a commonly used unit of length for measuring geographic distances in India.
The basic metric unit of measure for length is the meter (m).