If the base and height of a parallelogram are enlarged by 4 times at the same time, the area of the parallelogram will be enlarged by how many times.
一个平行四边形底和高同时扩大4倍，则平行四边形的面积就扩大多少倍．
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>