If a log with a length of 25 decimeters and a base radius of 2 decimeters is sawn into three cylinders, how much square decimeters will the surface area increase?
一个长25分米，底面半径2分米的圆木，把它平均锯成三个圆柱体，则表面积增加多少平方分米．
<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>