Cut the largest square out of a piece of rectangular paper with a length of 20 cm and a width of 12 cm. What is the perimeter of this square?
用一张长为20厘米，宽为12厘米的长方形纸剪成一个最大的正方形，那么这个正方形，的周长是多少？
<gadget id="calculator">12 * 4</gadget>
<output>48</output>

<result>48</result>