After cutting a circle into an approximate rectangle, the length of this rectangle is 25.12 cm, what is the radius of the original circle in cm?
把一个圆剪拼成一个近似的长方形后，这个长方形的长是25.12厘米，原来圆的半径是多少厘米．
<gadget id="calculator">2 / 3.14 / 2</gadget>
<output>0.318471</output>

<gadget id="calculator">25.12 * 0.318471</gadget>
<output>7.999992</output>

<result>7.999992</result>