If 3 squares with a side length of 3 cm are joined together to form a rectangle, what is the perimeter in cm?
边长是3厘米的正方形3个连接在一起，拼成一个长方形，它的周长是多少厘米
<gadget id="calculator">3 + 3 + 3 + 3</gadget>
<output>12</output>

<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<result>24</result>