A cylindrical wood with a length of 4 meters and a cross-sectional radius of 2 decimeters is cut into 4 sections of the same length, and the surface area is increased by how many square centimeters compared to the original.
一根长4米，横截面半径为2分米的圆柱形木料截成同样长的4段，表面积比原来增加多少平方厘米．
<gadget id="calculator">2 ** 2</gadget>
<output>4</output>

<gadget id="calculator">3.14 * 4 * 6 * 100</gadget>
<output>7_536</output>

<result>7_536</result>