If a circle with a circumference of 15.7 cm is drawn, what is the distance between the two corners of the compass in cm?
如果画一个周长15.7厘米的圆，那么圆规两角间的距离是多少厘米．
<gadget id="calculator">15.7 / 3.14 / 2</gadget>
<output>2.5</output>

<result>2.5</result>