If a cylinder with a base diameter of 2 decimeters is cut off by a cylinder with a height of 1 decimeter, the surface area of the original cylinder will be reduced by how many square decimeters.
把一个底面直径2分米的圆柱体截去一个高1分米的圆柱体，原来的圆柱体表面积减少多少平方分米．
<gadget id="calculator">3.14 * 2 * 1</gadget>
<output>6.28</output>

<result>6.28</result>