If a cylindrical piece of wood is cut into two sections, the surface area will increase by 25.12 square decimeters. What is the circumference of the bottom surface of this piece of cylindrical wood in decimeters?
一根圆柱形木料，如果把它拦腰截成两段，表面积就增加25.12平方分米，这段圆柱形木料的底面周长是多少分米？
<gadget id="calculator">2 * 3.14 * 2</gadget>
<output>12.56</output>

<result>12.56</result>