Cut the bottom surface of a cylinder with a height of 12 cm into several equal parts and assemble it into an approximate cuboid with an increase of 72 cm2 in surface area. Find the volume of the cylinder.
把一个高是12厘米的圆柱的底面切成若干等份，拼成一个近似的长方体，表面积增加了72平方厘米．求圆柱的体积．
<gadget id="calculator">72 / 2 / 12</gadget>
<output>3</output>

<gadget id="calculator">3 ** 2</gadget>
<output>9</output>

<gadget id="calculator">3.14 * 9 * 12</gadget>
<output>339.12</output>

<result>339.12</result>