A Ferris wheel is 20 meters from the highest point to the lowest point, how many meters does it turn around in the air when sitting on it?
一个摩天轮的最高点到最低点是20米，坐着它在空中转动一周约转过多少米．
<gadget id="calculator">3.14 * 20</gadget>
<output>62.8</output>

<result>62.8</result>