If you expand the sides of a cylinder to obtain a square with a side length of 5 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为5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">5 * 5</gadget>
<output>25</output>

<result>25</result>