To draw a circle with a circumference of 1.57 decimeters, what is the distance between the two legs of the compass in decimeters?
要画一个周长是1.57分米的圆，圆规的两脚之间的距离是多少分米．
<gadget id="calculator">2 * 3.14</gadget>
<output>6.28</output>

<gadget id="calculator">1.57 / 6.28</gadget>
<output>0.25</output>

<result>0.25</result>