The circumference of a circle is 18.84 cm, what is the area of the circle?
一个圆的周长是18.84厘米，求这个圆的面积是多少．
<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>