If 3 squares with an area of 1 square centimeter are put together to form a rectangle, what is the perimeter of the rectangle in centimeters?
用3个面积都是1平方厘米的正方形拼成一个长方形，长方形的周长是多少厘米．
<gadget id="calculator">1 * 3</gadget>
<output>3</output>

<gadget id="calculator">3 + 1</gadget>
<output>4</output>

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

<result>8</result>