Plant trees around a circular field with a diameter of 25m, and plant one tree every 1.57m. How many trees can be planted in total?
在一个直径是25m的圆形场地周围栽树，每隔1.57m栽一棵，一共可以栽多少棵？
<gadget id="calculator">25 / 1.57</gadget>
<output>15.923567</output>

<gadget id="calculator">3.14 * 15.923567</gadget>
<output>50</output>

<result>50</result>