The perimeter of two identical isosceles trapezoids is 19 centimeters, and the perimeter of a parallelogram is 32 centimeters. What is the waist length of an isosceles trapezoid?
两个完全一样的等腰梯形的周长都是19厘米，拼成一个平行四边形后的周长是32厘米．等腰梯形的腰长是多少厘米？
<gadget id="calculator">19 * 2</gadget>
<output>38</output>

<gadget id="calculator">38 - 32</gadget>
<output>6</output>

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<result>3</result>