There is a square flower bed in the school, and a circle of hedges is planted around it. The total length of the hedge is 36 meters. What is the area of this flower bed?
学校里有一个正方形花坛，四周种上了一圈绿篱，绿篱总长36米，这个花坛的面积是多少？
<gadget id="calculator">36 / 4</gadget>
<output>9</output>

<gadget id="calculator">9 * 9</gadget>
<output>81</output>

<result>81</result>