A rectangle and a square lawn are to be built in the park. The length of the rectangle is 25 meters and the width is 21 meters; the side length of the square is 25 meters. Which lawn has the largest area? How many square meters is it?
公园要建一个长方形和一个正方形草坪，长方形的长为25米，宽21米；正方形的边长为25米，哪个草坪的面积大？大多少平方米？
<gadget id="calculator">25 * 25</gadget>
<output>625</output>

<gadget id="calculator">25 * 21</gadget>
<output>525</output>

<gadget id="calculator">625 - 525</gadget>
<output>100</output>

<result>100</result>