If a cylinder with a length of 3 meters is cut into 3 sections, the surface area is increased by 12 square decimeters, what is the original volume of the cylinder in cubic decimeters?
把一个长3米的圆柱切成3段，表面积增加了12平方分米，这个圆柱的原来的体积为多少立方分米．
<gadget id="calculator">12 / 4</gadget>
<output>3</output>

<gadget id="calculator">3 * 3 * 10</gadget>
<output>90</output>

<result>90</result>