If a cylindrical steel bar with a length of 2 meters and a base radius of 2 decimeters is cut into 4 sections, the surface area will be increased by how many square decimeters.
把一根长2米，底面半径2分米的圆柱形钢材截成4段，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 * 6</gadget>
<output>75.36</output>

<result>75.36</result>