If the diameter of the base of a cylinder is 10 cm, if the height increases by 1 cm, what is the increase in the lateral area in square centimetres?
一个圆柱底面直径10cm，若高增加1cm，则侧面积增加多少平方厘米．
<gadget id="calculator">3.14 * 10 * 1</gadget>
<output>31.4</output>

<result>31.4</result>