Put a 2 meters. If a cylindrical steel material with an area of 3.14 square decimeters is cut into two equal sections, how much does the surface area increase?
把一根2米．地面积为3.14平方分米的圆柱形钢材截成相等的两段，表面积增加了多少．
<gadget id="calculator">3.14 * 2</gadget>
<output>6.28</output>

<result>6.28</result>