In a cuboid with a height of 25 cm, if its height is shortened by 5 cm, the surface area will be reduced by 40 cm2. The base of this cuboid is a square. What is the area of the base.
在一个高为25厘米的长方体中，如果把它的高缩短5厘米，表面积就减少40平方厘米，这个长方体的底面是正方形．则底面积是多少．
<gadget id="calculator">40 / 4 / 5</gadget>
<output>2</output>

<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<result>4</result>