A square flower bed has a perimeter of 36 meters, what is its area in square meters?
一个正方形花坛，周长是36米，它的面积是多少平方米．
<gadget id="calculator">36 / 4</gadget>
<output>9</output>

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

<result>81</result>