An isosceles triangular chicken coop is surrounded by 42-meter-long iron wire. Its base is 10 meters long. How many meters long is its waist?
用42米长的铁丝围成一个等腰三角形的鸡舍，它的底长10米，它的腰长几米？
<gadget id="calculator">42 - 10</gadget>
<output>32</output>

<gadget id="calculator">32 / 2</gadget>
<output>16</output>

<result>16</result>