If the largest circle is cut from a square with a circumference of 20dm, what is the area of the remaining part?
在一张周长20dm的正方形上剪下一个最大的圆，则剩余部分的面积是多少平方分米．
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) ** 2</gadget>
<output>25/4 = around 6.25</output>

<gadget id="calculator">3.14 * (25/4)</gadget>
<output>19.625</output>

<gadget id="calculator">25 - 19.625</gadget>
<output>5.375</output>

<result>5.375</result>