In a square piece of paper with a circumference of 100 cm, the largest circle is to be cut out. What is the radius of this circle in cm?
在一个周长为100CM的正方形纸片内，要剪一个最大的圆，这个圆的半径是多少厘米？
<gadget id="calculator">100 / 4</gadget>
<output>25</output>

<gadget id="calculator">25 / 2</gadget>
<output>25/2 = around 12.5</output>

<result>25/2 = around 12.5</result>