A 36cm long iron wire is used to form a rectangle so that its length is 12cm, what is its area?
用一根长36cm的铁丝围成一个长方形，使它的长为12cm，它的面积是多少？
<gadget id="calculator">36 / 2</gadget>
<output>18</output>

<gadget id="calculator">18 - 12</gadget>
<output>6</output>

<gadget id="calculator">12 * 6</gadget>
<output>72</output>

<result>72</result>