The circumference of a circular playground is 62.8 meters. When expanding, the radius increases by 1 meter. How many square meters does the area increase?
一个圆形游乐场的周长是62.8米，扩建时，半径增加了1米，面积增加了多少平方米？
<gadget id="calculator">62.8 / 3.14 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 + 1</gadget>
<output>11</output>

<gadget id="calculator">11 ** 2</gadget>
<output>121</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">121 - 100</gadget>
<output>21</output>

<gadget id="calculator">3.14 * 21</gadget>
<output>65.94</output>

<result>65.94</result>