Unwrap the side wrapping paper of a cylindrical food can to get a square. The radius of the bottom of this cylindrical can is 5 cm. What is the height of the cylinder?
把一个圆柱体食品罐头的侧面包装纸展开，得到一个正方形，这个圆柱体罐头的底面半径是5厘米，圆柱体的高是多少
<gadget id="calculator">2 * 3.14 * 5</gadget>
<output>31.4</output>

<result>31.4</result>