If the length of the rectangle is 10 cm and the width is 6 cm, what is the perimeter?
长方形的长是10厘米，宽是6厘米，周长是多少．
<gadget id="calculator">10 + 6</gadget>
<output>16</output>

<gadget id="calculator">16 * 2</gadget>
<output>32</output>

<result>32</result>