A cylinder has a radius of 5 decimeters at the base and a square when its sides are expanded. What is the height of this cylinder in meters.
一个圆柱的底面半径为5分米，侧面展开后是一个正方形．这个圆柱的高是多少米．
<gadget id="calculator">5 / 10</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">2 * 3.14 * (1/2)</gadget>
<output>3.14</output>

<result>3.14</result>