The radius of the base of a cylinder is 1 cm. If its height is shortened by 3 cm, its surface area will be reduced by how many square centimeters.
一个圆柱体的底面半径是1厘米，如果把它的高缩短3厘米，它的表面积减少多少平方厘米．
<gadget id="calculator">3.14 * 1 * 2 * 3</gadget>
<output>18.84</output>

<result>18.84</result>