Roll a piece of paper 9 decimeters long and 3 decimeters wide into a cylinder. What is the lateral area of the cylinder in square centimetres.
把一个长9分米，宽3分米的纸卷成一个圆柱．圆柱的侧面积是多少平方分米．
<gadget id="calculator">9 * 3</gadget>
<output>27</output>

<result>27</result>