Cut a circular iron piece as large as possible from a rectangular iron plate with a length of 8 decimeters and a width of 6 decimeters. What is the remaining area?
在长8分米，宽6分米的长方形铁板上，剪下一个尽可能大的圆形铁片，剩下的面积是多少平方分米？
<gadget id="calculator">8 * 6</gadget>
<output>48</output>

<gadget id="calculator">6 / 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>

<gadget id="calculator">48 - 28.26</gadget>
<output>19.74</output>

<result>19.74</result>