If a cylindrical piece of wood with a height of 1 meter is sawed into 3 sections, the surface area increases by 12 square meters. What is the volume of this piece of wood?
把一根高1米的圆柱形木料锯成3段，则表面积增加了12平方米，原来这根木料的体积是多少．
<gadget id="calculator">12 / 4</gadget>
<output>3</output>

<gadget id="calculator">3 * 1</gadget>
<output>3</output>

<result>3</result>