Use a piece of rectangular paper with a length of 6.5 cm and a width of 4 cm to form a cylindrical paper tube. What is the lateral area of the paper tube in square centimeters?
用一张长6.5厘米，宽4厘米的长方形纸，围成一个圆柱形纸筒，这个纸筒的侧面积是多少平方厘米．
<gadget id="calculator">6.5 * 4</gadget>
<output>26</output>

<result>26</result>