After unfolding the sides of a cylinder, a square is obtained. The diameter of the bottom of this cylinder is 10 cm. What is its height in cm?
把一个圆柱体侧面展开后，得到一个正方形，这个圆柱体底面直径是10厘米，它的高是多少厘米．
<gadget id="calculator">3.14 * 10</gadget>
<output>31.4</output>

<result>31.4</result>