If the sides of a cylinder are expanded to obtain a square with a side length of 4 decimeters, what is the lateral area of the cylinder in square decimeters?
把一个圆柱体的侧面展开得到一个边长4分米的正方形，这个圆柱体的侧面积是多少平方分米．
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>