Divide a cylinder into several equal parts and form an approximate cuboid, and the surface area increases by 9.6 square decimeters compared with the cylinder. If the height of the cylinder is 2.4 decimeters, what is the area of the bottom of the cylinder in square decimeters?
把一个圆柱体平均分成若干等份，拼成一个近似的长方体之后表面积比圆柱体增加了9.6平方分米，若圆柱体的高是2.4分米，则圆柱体的底面积是多少平方分米．
<gadget id="calculator">9.6 / 2 / 2.4</gadget>
<output>2</output>

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

<gadget id="calculator">3.14 * 4</gadget>
<output>12.56</output>

<result>12.56</result>