Question 417242
let the angles are, x, x, and (x+60)


==>  x + x + x + 60 = 180


==>  3x + 60 = 180

==>  3x + 60 - 60 = 180 -60

==>  3x   = 120

==> {{{3x/3   = 120/3}}}

==>  x   =  40


so the angles are  40,40, and 100