9 small squares with a side length of 1 cm are put together to form a large square. What is the area of the large square?
9个边长为1厘米的小正方形拼成一个大正方形，这个大正方形的面积是多少．
<gadget id="calculator">1 * 1 * 9</gadget>
<output>9</output>

<result>9</result>