Aunt Wang is going to use a 90 cm long wire to surround an isosceles triangle photo frame. If the waist is 35 cm long, how long is the bottom side?
王阿姨准备用一根90厘米长的铁丝围一个等腰三角形相框，如果腰长35厘米，底边长多少厘米？
<gadget id="calculator">90 - 35 - 35</gadget>
<output>20</output>

<result>20</result>