1m wide turf is laid around a circular pool with a diameter of 6m, what is the area of the turf in square meters?
在一个直径是6m的圆形水池周围铺1m宽的草皮，草皮的面积是多少平方米？
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<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>