The circumference of a circle is 12.56 cm. What is the longest line segment that can be drawn in this circle?
一个圆形的周长是12.56厘米，可以在这个圆里画一条最长的线段是多少厘米．
<gadget id="calculator">12.56 / 3.14</gadget>
<output>4</output>

<result>4</result>