If the perimeter of an isosceles triangle is 38 cm and the base is 12 cm long, what is the length of its waist in cm?
如果一个等腰三角形的周长是38厘米，底边长12厘米，它的腰长多少厘米．
<gadget id="calculator">38 - 12</gadget>
<output>26</output>

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

<result>13</result>