If two squares with a side length of 3 decimeters are put together to form a rectangle, what is the perimeter of the rectangle?
把2个边长是3分米的正方形拼成一个长方形，这个长方形的周长是多少？
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">6 + 3</gadget>
<output>9</output>

<gadget id="calculator">9 * 2</gadget>
<output>18</output>

<result>18</result>