Put together 9 squares with sides of 3 cm to form a large square. What is the perimeter of this large square in cm?
把9个边长是3厘米的正方形拼成一个大正方形，这个大正方形的周长是多少厘米？
<gadget id="calculator">3 * 3</gadget>
<output>9</output>

<gadget id="calculator">9 * 4</gadget>
<output>36</output>

<result>36</result>