A cylindrical wood with a cross-sectional radius of 10 cm, if the wood is cut into 5 sections of the same length, how much will the surface area increase in cm**2?
一根圆柱形木料，横截面半径是10cm，，如果将此木料截成同样长的5段，表面积比原来增加多少cm**2．
<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100 * 8</gadget>
<output>2_512</output>

<result>2_512</result>