If the height of a cylinder of wood is reduced by 3 decimeters, the surface area will be reduced by 18.84 square decimeters. What is the volume of the reduced part?
一个圆柱体木料，如果把高减少3分米，表面积就减少18.84平方分米，求减少部分的体积是多少？
<gadget id="calculator">18.84 / 3 / 3.14 / 2</gadget>
<output>1</output>

<gadget id="calculator">1 ** 2</gadget>
<output>1</output>

<gadget id="calculator">3.14 * 1 * 3</gadget>
<output>9.42</output>

<result>9.42</result>