A cylinder is surrounded by a square paper with a side length of 8 cm. What is the lateral area of the cylinder?
用一张边长8厘米的正方形纸围成一个圆柱，这个圆柱的侧面积是多少．
<gadget id="calculator">8 * 8</gadget>
<output>64</output>

<result>64</result>