To cut a circle with a circumference of 25.12 centimeters, at least how many square centimeters of square cardboard should be used?
要剪一个周长是25.12厘米的圆，至少要用面积是多少平方厘米的正方形纸板才比较合适？
<gadget id="calculator">25.12 / 3.14</gadget>
<output>8</output>

<gadget id="calculator">8 * 8</gadget>
<output>64</output>

<result>64</result>