The upper base of an isosceles trapezoid is 10 centimeters, the lower base is 5 centimeters, and the length of a waist is 6 centimeters. How many centimeters of rope is required to enclose this isosceles trapezoid?
一个等腰梯形的上底是10厘米，下底是5厘米，一条腰长6厘米，围成这个等腰梯形至少要多少厘米长的绳子．
<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">10 + 5 + 12</gadget>
<output>27</output>

<result>27</result>