If the length of a rectangle is 12 cm and the width is 10 cm, what is its perimeter in cm?
一个长方形的长是12厘米，宽是10厘米，它的周长是多少厘米．
<gadget id="calculator">12 + 10</gadget>
<output>22</output>

<gadget id="calculator">22 * 2</gadget>
<output>44</output>

<result>44</result>