Cut a circular piece of paper with a radius of 4 cm to form 4 equal cone sides, what is the circumference of the base of each cone in cm?
把一张半径4厘米的圆纸片剪开围成4个相等的圆锥的侧面，每个圆锥的底面周长是多少厘米．
<gadget id="calculator">4 / 4</gadget>
<output>1</output>

<gadget id="calculator">2 * 3.14 * 1</gadget>
<output>6.28</output>

<result>6.28</result>