Xiaoli has a square handkerchief with a side length of 2 decimeters. At least how many decimeters of silk ribbon is needed to surround it.
小丽有一块边长2分米的正方形手帕，至少要用多少分米长的绸带才能围一圈．
<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<result>8</result>