A 12-meter-long iron wire is folded into a rectangle. When the length is 3 times greater than the width, what is the area in square meters?
一根长为12米的铁丝折成一个长方形，当长比宽多3倍时，面积为多少平方米．
<gadget id="calculator">1 + 3 + 1</gadget>
<output>5</output>

<gadget id="calculator">12 / 2 / 5</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">(6/5) * 4</gadget>
<output>24/5 = around 4.8</output>

<gadget id="calculator">(24/5) * (6/5)</gadget>
<output>144/25 = around 5.76</output>

<result>144/25 = around 5.76</result>