If a circular piece of paper is cut in half to form a semicircle, its circumference is reduced by 3.42 square centimeters, so how many square centimeters is the area reduced?
将一个圆形纸片，去掉一半变成一个半圆后，其周长减少了3.42平方厘米，那么面积减少了多少平方厘米．
<gadget id="calculator">2 * 3.14 * 1</gadget>
<output>6.28</output>

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

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

<gadget id="calculator">3.14 + 2</gadget>
<output>5.14</output>

<gadget id="calculator">6.28 - 5.14</gadget>
<output>1.14</output>

<gadget id="calculator">3.42 / 1.14</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">3.14 * 9 * (1/2)</gadget>
<output>14.13</output>

<result>14.13</result>