A circular stage with a radius of 2.5 meters. Now for the needs of the performance, the surrounding area has been widened by 0.5 meters. How many square meters is the area of the stage larger than the original area?
一个圆形舞台，半径是2.5米．现在为了演出的需要，在周围加宽了0.5米，现在舞台的面积比原来的面积大多少平方米？
<gadget id="calculator">2.5 + 0.5</gadget>
<output>3</output>

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

<gadget id="calculator">2.5 ** 2</gadget>
<output>6.25</output>

<gadget id="calculator">9 - 6.25</gadget>
<output>2.75</output>

<gadget id="calculator">3.14 * 2.75</gadget>
<output>8.635</output>

<result>8.635</result>