Grandpa formed an isosceles triangle with a hose. Its circumference is 45 cm, and its waist is 14 cm long. How long is its base in cm?
爷爷用一根软管围成了一个等腰三角形，它的周长是45厘米，一条腰长14厘米，它的底边长多少厘米？
<gadget id="calculator">14 + 14</gadget>
<output>28</output>

<gadget id="calculator">45 - 28</gadget>
<output>17</output>

<result>17</result>