Question 924549
you know is {{{ABC + BCA + CAB = 180}}}

you also know it's a triangle



you know {{{5x + 8 + 6x + 22 + 3x - 25 = 180}}} 
{{{14x =175}}} 
{{{x = 12.5}}}

measure of each angle is:

 M< {{{BAC = 5X+8 = 70.5}}}
 M< {{{ABC=6X+22 = 97}}} 
M< {{{BCA=3X-25 = 12.5}}}

you also know that an measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles 

let's exterior angles be {{{A}}}, {{{B}}}, and {{{C}}} (the letter of each vertex)

then 

M< {{{A}}}=M< {{{ABC+BCA}}}=>M< {{{97+12.5}}}=>M< {{{109.5}}}

M< {{{B}}}=M< {{{BAC+BCA}}}=>M< {{{70.5+12.5}}}=>M< {{{83}}}

M< {{{C}}}=M< {{{BAC+ABC}}}=>M< {{{70.5+97}}}=>M< {{{167.5}}}


or, solve it using the sum of an exterior angle and its corresponding interior angle which is {{{180}}}

 exterior angle {{{A}}} and {{{BAC}}} sum up to {{{180}}}

so, 

{{{A=180-BAC=180-70.5=109.5}}}

{{{B=180-ABC=180-97=83}}}

{{{C=180-BCA=180-12.5=167.5}}}