Cut the largest circle in a rectangular paper with a length of 10 decimeters and a width of 6 decimeters, what is the area of this circle?
在一张长10分米宽6分米的长方形纸内剪一个最大的圆，则这个圆的面积的多少．
<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>

<result>28.26</result>