Mrs. Smith has 42 carpet squares. How should she arrange them so that she has the smallest perimeter?

2 answers

If Mrs. Smith wants the smallest perimeter out of her 42 carpet squares, she should arrange them in a square with each side having 10 carpet squares and the remaining two laid across the middle.

This will make a square-shaped area of 10 by 10 carpet squares, which will have a perimeter of 40 carpet squares. The two remaining carpet squares can be laid on top of each other in the middle of the square, so they won't affect the perimeter.

Any other arrangement will have a larger perimeter, since the distance around the edge of the square will be shorter than any other shape that can be made with 42 carpet squares.
I think they are supposed to form a solid area of carpet.
A square has the smallest perimeter, so we shpuld try to get as close to that as possible.
6x7 has a perimeter of 26