The base of a parallelogram is 65 meters and the height is 30 meters. If the base is increased by 20 meters, the area will be increased by how many square meters.
一个平行四边形的底是65米，高是30米，如果底增加20米，则面积增加多少平方米．
<gadget id="calculator">20 * 30</gadget>
<output>600</output>

<result>600</result>