Final answer:
The four main units of length in the U.S. are inches, feet, yards, and miles. The inch is the smallest unit and there are 12 inches in 1 foot. The foot is then used to measure longer distances, such as yards, which consist of 3 feet. Finally, miles are used for even larger distances.
Step-by-step explanation:
The four main units of length in the U.S. are inches, feet, yards, and miles. The inch is the smallest unit and there are 12 inches in 1 foot. The foot is then used to measure longer distances, such as yards, which consist of 3 feet. Finally, miles are used for even larger distances.