The side of a cylinder is unfolded to form a square. The radius of the base of the cylinder is 1 decimeter. How many decimeters is the height of the cylinder?
一个圆柱的侧面展开后刚好得到一个正方形，这个圆柱的底面半径为1分米，这个圆柱的高为多少分米？
<gadget id="calculator">3.14 * 1 * 2</gadget>
<output>6.28</output>

<result>6.28</result>