If the base of a parallelogram is doubled and the height is doubled, its area will be doubled.
平行四边形的底扩大到原来的2倍，高也扩大到原来的2倍，它的面积就扩大到原来的多少倍
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>