If a log with a radius of 2 decimeters and a length of 1 meter is cut into 2 sections on average, the total surface area will increase by how many square decimeters.
把一根半径2分米，长1米的圆木，平均截成2段，表面积共增加多少平方分米．
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 2</gadget>
<output>25.12</output>

<result>25.12</result>