Question 1200907
Either base angle, b
The vertex angle, 180-2b


Vertex angle is 10 degrees less than either base angle:
{{{180-2b=3b-10}}}
-
{{{190=5b}}}

{{{b=190/5}}}

{{{highlight_green(b=38)}}}



Vertex angle's measure,  {{{180-2*38}}}.

{{{highlight(104*degrees)}}}