After a cylinder with a length of 12 cm is cut off by 5 cm, the surface area of the cylinder is reduced by 31.4 square centimeters. What is the original lateral area of the cylinder in square centimeters?
一个长为12cm的圆柱被截去5cm后，圆柱的表面积减少了31.4平方厘米，原来圆柱的侧面积是多少平方厘米？
<gadget id="calculator">31.4 / 5</gadget>
<output>6.28</output>

<gadget id="calculator">6.28 * 12</gadget>
<output>75.36</output>

<result>75.36</result>