The volume of a cylinder is 31.4cm**3, the height is 6.28cm, what is the area of its bottom?
一个圆柱的体积是31.4cm**3，高是6.28cm，它的底面积是多少．
<gadget id="calculator">31.4 / 6.28</gadget>
<output>5</output>

<result>5</result>