There is a square garden on campus. The path around the garden is 72 meters long. What is the area of the garden in square meters?
校园里有一个正方形的花园，绕花园一周的小路长是72米，这个花园的面积是多少平方米？
<gadget id="calculator">72 / 4</gadget>
<output>18</output>

<gadget id="calculator">18 * 18</gadget>
<output>324</output>

<result>324</result>