A rope is used (1/5), exactly 6.28 meters. The remaining ropes form a circle, what is the area of the circle? (π takes 3.14)
一根绳子用去(1/5)，正好用去6.28米．剩下的绳子围成一个圆，圆的面积多少？(π取3.14)
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">6.28 / (1/5)</gadget>
<output>31.4</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">31.4 * (4/5)</gadget>
<output>25.12</output>

<gadget id="calculator">25.12 / 3.14 / 2</gadget>
<output>4</output>

<gadget id="calculator">4 ** 2</gadget>
<output>16</output>

<gadget id="calculator">3.14 * 16</gadget>
<output>50.24</output>

<result>50.24</result>