A rectangle with a length of 4 decimeters and a width of 2 decimeters, taking its long side as the axis, and after one rotation, what figure will be obtained? What is the volume of this solid figure?
一个长为4分米，宽为2分米的长方形，以它的长边为轴，旋转一周后，得到的是一个什么图形？这个立体图形的体积是多少？
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 4</gadget>
<output>50.24</output>

<result>50.24</result>