The diameter of a circular lake is 2,100 meters. How many weeping willows can be planted every 3 meters along its edge?
一个圆形湖泊的直径是2100米，沿着他它的边线每隔3米栽一棵垂柳，可以栽多少棵？
<gadget id="calculator">2_100 / 3</gadget>
<output>700</output>

<gadget id="calculator">3.14 * 700</gadget>
<output>2_198</output>

<result>2_198</result>