Xiaofang enlarges the side length of a square with an area of 4 square centimeters at a ratio of 2:1. What is the area of the enlarged square in square centimeters?
小芳把一个面积4平方厘米的正方形的边长按2：1的比例放大，放大后的正方形的面积是多少平方厘米．
<gadget id="calculator">2 * 2 * 2 * 2</gadget>
<output>16</output>

<result>16</result>