The lateral area of a cylinder is 502.4 square decimeters, the height is 8 decimeters, what is the diameter of its bottom surface in decimeters.
一个圆柱的侧面积是502.4平方分米，高是8分米，它的底面直径是多少分米．
<gadget id="calculator">502.4 / 8 / 3.14</gadget>
<output>20</output>

<result>20</result>