The upper base of a trapezoid is enlarged to 4 times its original size, and the lower base is also enlarged to 4 times its original size. If the height remains the same, what is its area?
一个梯形的上底扩大为原来的4倍，下底也扩大为原来的4倍，如果高不变，它的面积多少．
<result>4</result>