If a square board with a side length of 2 meters is used to make the largest round table, what is the area of the removed part?
一块边长2米的正方形木板，如果用它做一个最大的圆桌面，去掉部分的面积是多少平方米？
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">2 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1</gadget>
<output>3.14</output>

<gadget id="calculator">4 - 3.14</gadget>
<output>0.86</output>

<result>0.86</result>