The height of a cylinder is 12.56cm, and its sides are expanded to form a square. What is the diameter of the base of the cylinder in cm?
一个圆柱的高是12.56cm，它的侧面展开后是一个正方形，这个圆柱的底面直径是多少cm．
<gadget id="calculator">12.56 / 3.14</gadget>
<output>4</output>

<result>4</result>