Draw a circle with the legs of a compass 4 cm apart, what is the circumference of the circle in cm
把圆规的两脚张开4cm画一个圆，画出的圆的周长是多少cm
<gadget id="calculator">3.14 * 4 * 2</gadget>
<output>25.12</output>

<result>25.12</result>