The perimeter of an isosceles triangle is 90 cm and the base is 24 cm. What is the waist length of this triangle?
等腰三角形的周长是90厘米，底边长24厘米，这个三角形的腰长是多少厘米？
<gadget id="calculator">90 - 24</gadget>
<output>66</output>

<gadget id="calculator">66 / 2</gadget>
<output>33</output>

<result>33</result>