Draw a circle with a circumference of 25.12 centimeters, and use a compass to measure the distance in centimeters on the ruler.
画一个周长是25.12厘米的圆，用圆规两脚在直尺上取多少厘米的距离．
<gadget id="calculator">25.12 / 3.14 / 2</gadget>
<output>4</output>

<result>4</result>