A circular stage with a radius of 3 meters is now widened by 1 meter around it for performance needs. How many square meters is the area of the stage larger than the original area?
一个圆形舞台，半径3米，现在为了演出的需要，在周围加宽1米，现在舞台面积比原来面积大多少平方米？
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

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

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

<gadget id="calculator">16 - 9</gadget>
<output>7</output>

<gadget id="calculator">3.14 * 7</gadget>
<output>21.98</output>

<result>21.98</result>