The diameter of the base of a cylinder is 10 cm, if the height is reduced by 2 cm, how much will the surface area be reduced?
一个圆柱的底面直径是10cm，若高减少2cm，则表面积减少多少．
<gadget id="calculator">3.14 * 10 * 2</gadget>
<output>62.8</output>

<result>62.8</result>