If a rectangular wire frame with a length of 28 cm and a width of 12 cm is converted into the largest square, what is the area of this square?
把一个长28厘米，宽12厘米的长方形铁丝框架改做成一个最大的正方形，这个正方形的面积是多少？
<gadget id="calculator">28 + 12</gadget>
<output>40</output>

<gadget id="calculator">2 / 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">40 * (1/2)</gadget>
<output>20</output>

<gadget id="calculator">20 * 20</gadget>
<output>400</output>

<result>400</result>