A cylinder whose sides are unfolded is a square with side length 12.56 cm. What is the diameter of the base of the cylinder in cm?
一个圆柱体侧面展开后是一个边长12.56厘米的正方形，这个圆柱体的底面直径是多少厘米．
<gadget id="calculator">12.56 / 3.14</gadget>
<output>4</output>

<result>4</result>