The perimeter of an isosceles trapezoid is 62 cm, the lower base is 6 cm longer than the upper base, and the waist is 15 cm. What is the length of the bottom of this trapezoid?
等腰梯形的周长是62厘米，下底比上底长6厘米，腰长为15厘米．这个梯形的下底长多少厘米？
<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<gadget id="calculator">62 - 6 - 30</gadget>
<output>26</output>

<gadget id="calculator">1 + 1</gadget>
<output>2</output>

<gadget id="calculator">26 / 2</gadget>
<output>13</output>

<gadget id="calculator">13 + 6</gadget>
<output>19</output>

<result>19</result>