If the side length of a square is 6 cm, if the side length is increased by 2 cm, the perimeter will increase by how many cm.
一个正方形的边长是6厘米，把它的边长增加2厘米后，周长增加了多少厘米．
<gadget id="calculator">2 * 4</gadget>
<output>8</output>

<result>8</result>