If the perimeter of a square is 3.6 meters, what is the area of the square?
一个正方形的周长是3.6米，这个正方形的面积是多少．
<gadget id="calculator">3.6 / 4</gadget>
<output>0.9</output>

<gadget id="calculator">0.9 * 0.9</gadget>
<output>0.81</output>

<result>0.81</result>