The perimeter of the rectangle ABCD is 14 cm. Draw a square on each side whose length is that side. Given that the sum of the areas of these four squares is 50 square centimeters, what is the area of the rectangle ABCD in square centimeters?
长方形ABCD的周长是14厘米，在它的每条边上各画一个以该边为边长的正方形．已知这四个正方形的面积和是50平方厘米，那么长方形ABCD的面积是多少平方厘米．
<gadget id="calculator">3 * 4</gadget>
<output>12</output>

<result>12</result>