A copper bar with a length of 150 cm is to be made into an isosceles triangle with a waist length of 45 cm. What is the length of its base in cm? (The length at the joint is ignored)
一根长150厘米的铜条，要把它做成一个腰长是45厘米的等腰三角形，它的底边长是多少厘米？(接头处的长度忽略不计)
<gadget id="calculator">45 * 2</gadget>
<output>90</output>

<gadget id="calculator">150 - 90</gadget>
<output>60</output>

<result>60</result>