A cylindrical piece of wood is cut into three sections along the direction perpendicular to the height. If the area of the bottom is 20 square centimeters, how much does the surface area of the wood increase by how many square centimeters?
一根圆柱形木料，把它沿垂直于高的方向截成3段，如果底面积是20平方厘米，这时木料的表面积增加多少平方厘米．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<result>80</result>