After cutting a cylinder into an approximate cuboid, the surface area increases by 50 square centimeters. What is the lateral area of the cylinder?
把一个圆柱切拼成一个近似的长方体后，表面积增加了50平方厘米，圆柱的侧面积是多少．
<gadget id="calculator">3.14 * 2 * 25</gadget>
<output>157</output>

<result>157</result>