How much does the surface area increase when a cylindrical piece of wood with a length of 3 meters and a diameter of 4 decimeters at the bottom is sawn into 3 sections?
把一根长是3米，底面直径是4分米的圆柱形木料锯成3段后，表面积增加了多少．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<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>