A cylindrical piece of wood is 4 meters long and has a base radius of 3 decimeters. When it is cut into 3 sections (the cross section is parallel to the base), how many square centimeters does the surface area increase?
一根圆柱形木头长4米，底面半径是3分米，把它截成3段后(截面平行于底面)，表面积增加了多少平方厘米．
<gadget id="calculator">3 * 10</gadget>
<output>30</output>

<gadget id="calculator">30 ** 2</gadget>
<output>900</output>

<gadget id="calculator">3.14 * 900 * 4</gadget>
<output>11_304</output>

<result>11_304</result>