11. (Shanghai - Senior High School) Given that one side of a rectangle is $m$ cm, three mutually perpendicular lines divide this rectangle into 4 smaller rectangles, where the area of 3 of the smaller rectangles is no less than $m$ square cm, and the area of the 4th smaller rectangle is no less than $2m$ square cm, then the minimum possible value of the other side of this rectangle is
11.
$$
3+2 \sqrt{2} \text {. }
$$