If a cylindrical wood with a base radius of 2 decimeters and a length of 9 decimeters is sawed into three small pieces of cylindrical wood with different lengths, how many square decimeters will the surface area increase?
把一个底面半径是2分米，长9分米的圆柱形木头锯成长短不同的三小段圆柱形木头，表面积增加了多少平方分米．
<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>