If the length of a rectangle is reduced by 5 centimeters, the area will be reduced by 40 square centimeters, and the rest is exactly a square. What is the area of the original rectangle in square centimeters?
一个长方形的长如果减少5厘米，面积就减少40平方厘米，剩下的恰好是个正方形，原长方形的面积是多少平方厘米．
<gadget id="calculator">40 / 5</gadget>
<output>8</output>

<gadget id="calculator">5 + 8</gadget>
<output>13</output>

<gadget id="calculator">13 * 8</gadget>
<output>104</output>

<result>104</result>