There is a cylinder with a height of 10 cm and a base radius of 5 cm. If the height is reduced by 2 cm, how much will the lateral area be reduced by π square centimeters?
有一个圆柱体，高是10厘米，底面半径是5厘米，若高减少2厘米，则侧面积减少多少π平方厘米
<gadget id="calculator">5 * 2 * 2</gadget>
<output>20</output>

<result>20</result>