Stack three pieces of cylindrical wood with a base diameter of 20 cm. If one piece is added, the surface area will increase by 942 square centimeters. What is the volume of each piece of wood?
把3截底面直径都是20厘米的圆柱形木材叠放在一起，如果添上一截，表面积就比原来增加942平方厘米，每截木材的体积是多少？
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 20</gadget>
<output>62.8</output>

<gadget id="calculator">942 / 62.8</gadget>
<output>15</output>

<gadget id="calculator">3.14 * 100 * 15</gadget>
<output>4_710</output>

<result>4_710</result>