The area of a parallelogram is 20dm**2, if the base and height are reduced by 2 times, what is its area?
一个平行四边形的面积是20dm**2，如果底和高都缩小2倍，则它的面积是多少．
<gadget id="calculator">20 / 2 / 2</gadget>
<output>5</output>

<result>5</result>