A rectangular carpet is 28 cm long and 15 cm wide, find the perimeter of the carpet.
一块长方形的地毯长28厘米，宽15厘米，求地毯的周长．
<gadget id="calculator">28 + 15</gadget>
<output>43</output>

<gadget id="calculator">43 * 2</gadget>
<output>86</output>

<result>86</result>