A rectangular lawn has an area of 420 square meters and a length of 30 meters. If the width remains the same and the length is increased to 90 meters, what is the area in square meters?
一个长方形草坪的面积是420平方米，长是30米．如果宽不变，将长增加到90米后，面积是多少平方米？
<gadget id="calculator">90 / 30</gadget>
<output>3</output>

<gadget id="calculator">3 * 420</gadget>
<output>1_260</output>

<result>1_260</result>