Expand a cylinder sideways to get a square. The radius of the bottom of this cylinder is 0.5 decimeters. What is the height of the cylinder?
把一个圆柱体侧面展开，得到一个正方形，这个圆柱体底面半径是0.5分米，圆柱体的高是多少分米？
<gadget id="calculator">2 * 3.14 * 0.5</gadget>
<output>3.14</output>

<result>3.14</result>