How many?

Feet

The foot is a unit of length in the British imperial and United States customary systems of measurement. Since the International Yard and Pound Agreement of 1959, one foot is defined as 0.3048 meters exactly. In both customary and imperial units, one foot comprises 12 inches and one yard comprises three feet. The foot is taken from the average length of a mans foot, but in older times was just uner 12 inches.

Hands

The hand is a unit of measurement of length standardized to 4 in (101.6 mm). It is used to measure the height of horses in many English-speaking countries, including Australia, Canada, the Republic of Ireland, the United Kingdom, and the United States. It was originally based on the breadth of a human hand. The average shire horse is 16 to 17 hands tall and can even reach up to 18 hands.