Cut a square paper with a circumference of 24 decimeters into the largest circle. What is the area of each of these circles?
把一张周长24分米的正方形纸剪成一个最大的圆．这个圆的面积各是多少？
<gadget id="calculator">24 / 4 / 2</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<result>28.26</result>