Physics question about the height of horse?

Question

The height of a horse is sometimes given in units of "hands." Why was this poor standard of length before it was redefined to refer to exactly 4 in.?

im not asking you to do my entire homework for me, i just don't get this question.

Answer 1

The measurement of a "hand" is the approximate distance from one side of a grown man's hand to the other.

That way, old cowboys could simply place their hands (They're going across the first knuckles of their fingers), up the animal's legs, til they hit the withers and they'd know the approximate height of their horse.

Answer 2

Not all hands are created equal.  One man's measure is longer than another's.  But it was convenient, because you'll always have the 'ruler' with you.