Red Sun Plaza used to have a rectangular flower garden, 40 meters long, which was increased by 20 meters when it was expanded, resulting in an increase of 400 square meters in area. How many square meters does this garden now cover?
红太阳广场原有一个长方形花圃，长40米，后来扩建时把长增加了20米，结果面积增加了400平方米．这个花圃现在占地面积是多少平方米？
<gadget id="calculator">40 + 20</gadget>
<output>60</output>

<gadget id="calculator">400 / 20</gadget>
<output>20</output>

<gadget id="calculator">60 * 20</gadget>
<output>1_200</output>

<result>1_200</result>