The perimeter of an isosceles triangle is 36 cm, the ratio of the waist to the base is 5:8, what is the base of the triangle in cm?
一个等腰三角形的周长是36厘米，腰和底边的比是5：8，这个三角形的底是多少厘米？
<gadget id="calculator">5 + 5 + 8</gadget>
<output>18</output>

<gadget id="calculator">8 / 18</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">36 * (4/9)</gadget>
<output>16</output>

<result>16</result>