The circumference of a piece of square paper is 12 decimeters, if it is cut into the largest circle, what is the circumference of the circle?
一张正方形纸的周长是12分米，把它剪成一个最大的圆形，那么圆的周长是多少分米．
<gadget id="calculator">12 / 4</gadget>
<output>3</output>

<gadget id="calculator">3.14 * 3</gadget>
<output>9.42</output>

<result>9.42</result>