After the length of a rectangle is shortened by 4 cm, its area is reduced by 16 cm2. If the remaining part is a square, what is the area of the original rectangle?
一个长方形的长缩短4厘米后，它的面积减少16平方厘米，如果剩下的部分是一个正方形，原长方形的面积是多少平方厘米？
<gadget id="calculator">16 / 4</gadget>
<output>4</output>

<gadget id="calculator">4 + 4</gadget>
<output>8</output>

<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<result>32</result>