The radius of the large circle is four times that of the small circle, and the area of the large circle is how many times the area of the small circle.
大圆的半径是小圆的4倍，大圆面积是小圆面积的多少倍倍．
<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<result>16</result>