A rectangle has a length of 18 cm and a width of 10 cm less than its length. What is the perimeter in cm?
一个长方形，长18厘米，宽比长少10厘米，周长是多少厘米．
<gadget id="calculator">18 - 10</gadget>
<output>8</output>

<gadget id="calculator">18 + 8</gadget>
<output>26</output>

<gadget id="calculator">26 * 2</gadget>
<output>52</output>

<result>52</result>