An isosceles trapezoid has an upper base of 15 decimeters, a lower base of 37 decimeters, and a waist of 34 decimeters. What is the perimeter of this isosceles trapezoid?
一个等腰梯形，上底为15分米，下底为37分米，腰为34分米，这个等腰梯形的周长是多少分米？
<gadget id="calculator">34 * 2</gadget>
<output>68</output>

<gadget id="calculator">68 + 15 + 37</gadget>
<output>120</output>

<result>120</result>