If a cylinder with a base diameter of 5 decimeters is cut off by a section with a length of 3 decimeters, how much square decimeters will the surface area of the original cylinder be reduced?
把一个底面直径为5分米的圆柱，截去长3分米的一段后，原来的圆柱表面积减少了多少平方分米．
<gadget id="calculator">3.14 * 5 * 3</gadget>
<output>47.1</output>

<result>47.1</result>