Cut the cylinder and assemble it into a cuboid. The surface area of the figure is 5 square decimeters larger than the original one. What is the side area of the original cylinder?
将圆柱切开后拼成一个长方体，图形的表面积比原来多5平方分米，原来圆柱的侧面积是多少．
<gadget id="calculator">5 * 3.14</gadget>
<output>15.7</output>

<result>15.7</result>