If a square with a side length of 3.2 decimeters is formed into a cylindrical paper tube, what is the side area of the paper tube in square decimeters?
把一张边长为3.2分米的正方形，围成一个圆柱形纸筒，这个纸筒的侧面积是多少平方分米．
<gadget id="calculator">3.2 * 3.2</gadget>
<output>10.24</output>

<result>10.24</result>