A cylinder is formed by a piece of rectangular paper with a length of 10 cm and a width of 5 cm. What is the lateral area of the cylinder in square centimeters?
用一张长10厘米，宽5厘米的长方形纸，围成一个圆柱，这个圆柱体的侧面积是多少平方厘米．
<gadget id="calculator">10 * 5</gadget>
<output>50</output>

<result>50</result>