Mia is building a three-sided shelter for her action figures. The shelter will resemble a rectangle with one of the long sides removed. She has boards that measure 36 inches, 39 inches, and 42 inches in length; all the boards are the same width. Mia will need to convert some of these measurements into other imperial units to build the shelter the way she wants.

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.

What is the width of the shelter, measured in feet?

Since the width is shorter than the length, the width must be less than 3.25 feet.

We know that 1 foot is equal to 12 inches.

To convert from inches to feet, we divide the number of inches by 12.

To find the width of the shelter in feet, we need to figure out which board length is less than 3.25 feet.

Let's convert the lengths of the boards from inches to feet:

36 inches = 36/12 = 3 feet
39 inches = 39/12 = 3.25 feet
42 inches = 42/12 = 3.5 feet

We see that the 39-inch board is equal to 3.25 feet, which matches the length Mia wants.

Since the width of the board must be less than the length, and we have a board that is 3 feet long, the width of the shelter must be less than 3 feet.