A basketball court is a rectangle with a length of 28 meters and a width of 15 meters. What is its perimeter?
篮球场是个长方形，长28米，宽15米，那么它的周长是多少．
<gadget id="calculator">28 + 15</gadget>
<output>43</output>

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

<result>86</result>