A piece of rectangular paper with a length of 12 cm and a width of 9 cm should be cut into the largest square. What is the perimeter of the square in cm?
一张长方形的纸，长12厘米，宽9厘米，要剪一个最大的正方形，正方形的周长是多少厘米．
<gadget id="calculator">9 * 4</gadget>
<output>36</output>

<result>36</result>