If you make a circle with a radius of 2 centimeters out of wire, what is the length in centimeters after making it into a square?
用铁丝做一个半径2厘米的圆，把它改做成正方形后边长是多少厘米．
<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

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

<result>3.14</result>