If the perimeter of a square flower pond is 60 meters, what is the area in square meters?
一个正方形花池周长是60米，面积是多少平方米．
<gadget id="calculator">60 / 4</gadget>
<output>15</output>

<gadget id="calculator">15 * 15</gadget>
<output>225</output>

<result>225</result>