Question

why can a pace or a footstep not use as standard unit .of lenght?​

Answer 1

Answer:

Answer: Standard unit of length is a fixed length all over the world, which does not vary with time, place and persons and is not affected by any natural phenomenon. A pace or a footstep cannot be used as a standard unit of length as it is not fixed in length and varies from person to person.

Answer 2

Answer and explanation: It is because a pace or a footstep of each and every person is not equal. They may vary in size, which caused confusion and incorrect measurements and a need to get a new measuring system which is correct emerged, which is now so called SI units, which is accepted by the world internationally.