A cylindrical piece of wood with a length of 3.6 meters, after sawing it horizontally into three sections, the surface area increases by 2.8 square meters, what is the original volume of the wood?
一根长3.6米的圆柱形木材，将它横锯成三段后，表面积增加2.8平方米，这根木材原来的体积是多少．
<gadget id="calculator">2.8 / 4</gadget>
<output>0.7</output>

<gadget id="calculator">0.7 * 3.6</gadget>
<output>2.52</output>

<result>2.52</result>