The diameter of the bottom surface of a cylindrical tin can is 10cm, the height is 8cm, how many cm is the label paper stuck on the side**2.
圆柱形铁罐底面直径为10cm，高为8cm，侧面粘的商标纸有多少cm**2．
<gadget id="calculator">3.14 * 10 * 8</gadget>
<output>251.2</output>

<result>251.2</result>