Draw the largest circle in a square whose circumference is 24 cm. What is the circumference of the circle?
在一个周长是24cm的正方形里画一个最大的圆，圆的周长是多少．
<gadget id="calculator">24 / 4</gadget>
<output>6</output>

<gadget id="calculator">3.14 * 6</gadget>
<output>18.84</output>

<result>18.84</result>