A 3-meter-long steel cylinder is cut into 3 sections on average, and the surface area increases by 12.56 square decimeters. What is the cross-sectional area?
一根3米长的圆柱体钢材平均截成3段，表面积增加了12.56平方分米，横截面的面积是多少？
<gadget id="calculator">12.56 / 4</gadget>
<output>3.14</output>

<result>3.14</result>