Question 764258
Vertex angle = x
Base angle = 30 + 4x
Total of 180 degrees in a triangle.
2(30 + 4x) + x = 180
  60 + 8x + x = 180
       60 + 9x = 180
            9x = 180 - 60
            9x = 120
             x = 120/9
             x = 13.3 degrees
Base angle = 83.3 degrees.
Hope this helps.
:-)