Mia will use one of these boards for the length of the shelter. She knows she wants

the length of the shelter to measure 3.25 feet. She will use a different board for the
width of the shelter. The width of the shelter will be shorter than the length.
Which board will Mia use for the length of the shelter, given that 1 foot = 12 inches?

To determine which board Mia will use for the length of the shelter, we need to convert 3.25 feet to inches.

Since 1 foot = 12 inches, we can multiply 3.25 by 12 to convert feet to inches: 3.25 feet * 12 inches/foot = 39 inches.

Therefore, Mia will use a board that is 39 inches long for the length of the shelter.