In a square fish pond, if a group of opposite sides is increased by 12 meters, the area will increase by 180 square meters. How many square meters is this square fish pond originally?
一个正方形的鱼池中，如果一组对边各增加12米，那么面积就增加180平方米．这个正方形鱼池原来有多少平方米？
<gadget id="calculator">180 / 12</gadget>
<output>15</output>

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

<result>225</result>