Answer:
It's not.
Step-by-step explanation:
The measure 'foot' came from the French Emperor Charlegmane. He proclaimed that the length of his foot is now a measurement. Unless your foot is exactly as big as Charlegmane's foot, it's not a foot.
King George had feet that had a foot long
Back in the old-old-OLDEN days, King George had a foot (obviously). And it was a foot long!
