For a square, if one side is increased by 6 cm and the other side is increased by 2 cm, the area of the resulting large rectangle is 108 cm2 larger than that of the original square. Find the side length of the original square.
一个正方形，如果一条边增加6厘米，另一条边增加2厘米，所得的大长方形面积比原来的正方形增加了108平方厘米．求原正方形的边长．
<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<result>12</result>