With a rope, the length of a circle around a big tree trunk is 1.57 meters. What is the diameter of this big tree in centimeters?
用一根绳子，在一棵大树干上绕一周的长度是1.57米．这棵大树的直径是多少厘米？
<gadget id="calculator">1.57 / 3.14</gadget>
<output>0.5</output>

<gadget id="calculator">0.5 * 100</gadget>
<output>50</output>

<result>50</result>