If a square flowerbed covers an area of 1 hectare, if the side length is doubled, how many hectares will the area of the flowerbed increase?
一个占地1公顷的正方形花圃，如果边长扩大两倍，花圃的面积会增加多少公顷？
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">1 * 3</gadget>
<output>3</output>

<result>3</result>