The measurements of an average door are 80 inches by 36 inches. In this measurement, the length is 80 inches and the width is 36 inches. If Hank estimates the width of the door of his classroom, he will then most likely estimate it at 36 inches. To convert this into feet, you must know that 12 inches make 1 foot. So, 36 inches divided by 12 inches will convert the measurement to feet: 36/12 = 3. Thus, the answer is 3 feet.