A circular fish pond has a radius of 12 meters. If it is transformed into a square fish pond, but the perimeter of the fish pond cannot be changed, then how many meters is the side length of the square fish pond?
一个圆形鱼塘半径是12米，将它改造成一个正方形的鱼塘，但不能改变鱼塘的周长，那么正方形鱼塘的边长是多少米？
<gadget id="calculator">3.14 / 4</gadget>
<output>0.785</output>

<gadget id="calculator">12 * 2 * 0.785</gadget>
<output>18.84</output>

<result>18.84</result>