A circular piece of paper, the diameter of the inner circle is 8 cm, and the distance between the two circles is 2 cm, what is the area of this circular piece of paper in square centimeters?
一张圆环纸片，内圆直径是8厘米，两圆间的距离是2厘米，这个圆环纸片的面积是多少平方厘米？
<gadget id="calculator">8 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">6 ** 2</gadget>
<output>36</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">36 - 16</gadget>
<output>20</output>

<gadget id="calculator">3.14 * 20</gadget>
<output>62.8</output>

<result>62.8</result>