Use 16 sticks with a length of 1dm to enclose a rectangle (including a square), what is the largest area in dm**2.
用16根长为1dm的小棒围成长方形(包括正方形)，其中面积最大是多少dm**2．
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>