Grandma Li's family planted a square vegetable field with a side length of 20 meters last year. In order to increase income, she increased the side length of this square vegetable field by 5 meters this year. How many square meters has the area of this vegetable field increased?
李奶奶家去年种植了一块边长是20米的正方形蔬菜地，为了增加收入，今年她把这块正方形蔬菜地的边长都增加了5米．这块蔬菜地的面积增加了多少平方米？
<gadget id="calculator">5 + 20</gadget>
<output>25</output>

<gadget id="calculator">25 * 25</gadget>
<output>625</output>

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

<gadget id="calculator">625 - 400</gadget>
<output>225</output>

<result>225</result>