The volume of a cone is 12.56 cubic decimeters, the height is 4 decimeters, what is the area of the base in square decimeters?
一个圆锥的体积是12.56立方分米，高是4分米，底面积是多少平方分米．
<gadget id="calculator">12.56 / 4</gadget>
<output>3.14</output>

<gadget id="calculator">3 * 3.14</gadget>
<output>9.42</output>

<result>9.42</result>