If three squares with an area of 1 square decimeter are put together to form a rectangle, what is the perimeter of the rectangle?
用三个面积是1平方分米的正方形拼成一个长方形，这个长方形的周长是多少分米．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<result>8</result>