Plant trees around a circular flower bed with a radius of 20 meters, and plant a tree every 6.28 meters. How many trees can be planted in total?
在一个半径为20米的圆形花坛周围栽树，每隔6.28米栽一棵树，一共可以栽多少棵树？
<gadget id="calculator">3.14 / 6.28</gadget>
<output>0.5</output>

<gadget id="calculator">20 * 2 * 0.5</gadget>
<output>20</output>

<result>20</result>