The ring width of the circular runway is 1 meter. If you only run one corner, how many meters should the starting point of the outside track be ahead of the inside track?
环形跑道的环宽是1米，如果只跑一个弯，外道选手的起跑点要比内道提前多少米．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

<result>3.14</result>