rectangular fish pond, after it is expanded, the length changes from 28 meters to 35 meters, the width remains the same, and the area increases by 112 square meters. What is the area of the fish pond after the expansion?
一个长方形鱼塘，现将它扩建后，长由28米变为35米，宽不变，面积增加了112平方米，则扩建后鱼塘的面积是多少？
<gadget id="calculator">35 - 28</gadget>
<output>7</output>

<gadget id="calculator">112 / 7</gadget>
<output>16</output>

<gadget id="calculator">35 * 16</gadget>
<output>560</output>

<result>560</result>