Draw a 3” x 4” square
The create 12 1x1 inch squares.
Count the number of squares that make up the border
You get 10 1x1 inch squares or 10 square inches.
You made up your own description of what the border should be. It could as easily be a cording, no width at all.
The answers are units, not square units. The question is asking for the perimeter.