A square with side length 20 cm. Now it is reduced according to the ratio of 1:4, so how many centimeters is the side length after reduction, and the area is the original ((())/(())).
一个边长20厘米的正方形．现在按照1：4的比例缩小，那么缩小后的边长是多少厘米，面积是原来的((())/(()))．
<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<result>5</result>