A cylinder is surrounded by a square piece of paper with a side length of 6 cm (not counting the joints). What is the side area of the cylinder in square centimeters?
用一张边长是6厘米的正方形纸片围成一个圆柱形(接口处不计)，这个圆柱形的侧面积是多少平方厘米．
<gadget id="calculator">6 * 6</gadget>
<output>36</output>

<result>36</result>