If a cylindrical piece of wood with a diameter of 20 cm and a length of 2 decimeters is sawn into 3 identical sections, how much does the surface area increase in square centimetres?
把一根直径是20厘米，长2分米的圆柱木材锯成同样的3段，表面积增加了多少平方厘米．
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

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

<gadget id="calculator">3.14 * 100 * 4</gadget>
<output>1_256</output>

<result>1_256</result>