An old lady walks around a circular flower bed in the park in the middle of the street, and walks 18.84 meters. How many square meters does the flower bed occupy?
一位老奶奶沿着街心公园的一个圆形花坛走了一圈，走了18.84米，花坛占地多少平方米．
<gadget id="calculator">18.84 / 3.14 / 2</gadget>
<output>3</output>

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

<gadget id="calculator">3.14 * 9</gadget>
<output>28.26</output>

<result>28.26</result>