A rectangular pillowcase, 80 cm long and 30 cm wide. How many centimeters of lace should be used to sew lace around?
一个长方形枕头套，长80厘米，宽30厘米．四周缝上花边，要用多少厘米花边？
<gadget id="calculator">80 + 30</gadget>
<output>110</output>

<gadget id="calculator">110 * 2</gadget>
<output>220</output>

<result>220</result>