The circumference of a circle is 28.26 meters, what is its area?
一个圆的周长是28.26米，它的面积是多少．
<gadget id="calculator">28.26 / 3.14 / 2</gadget>
<output>4.5</output>

<gadget id="calculator">4.5 ** 2</gadget>
<output>20.25</output>

<gadget id="calculator">3.14 * 20.25</gadget>
<output>63.585</output>

<result>63.585</result>