If the length of a rectangle is 5 cm and the width is 2 cm, what is the perimeter in cm?
一个长方形的长是5厘米，宽是2厘米，周长是多少厘米．
<gadget id="calculator">5 + 2</gadget>
<output>7</output>

<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<result>14</result>