If the perimeter of a rectangle is 13 meters and the length and width of the rectangle are increased by 2 meters, how many square meters will the area of the rectangle increase?
一个长方形的周长13米，长方形的长和宽都增加2米后，长方形的面积增加多少平方米？
<gadget id="calculator">13 + 4</gadget>
<output>17</output>

<result>17</result>