The measures are:
BAC = 180° - 13*6 + 3 = 105°
FAB = 13*6 - 3 = 75°
How to find the missing angles?
we know that the sum of the 3 interior angles of any triangle must be 180°, and we know that two adjacent angles always add up to 180°, then we know that:
A = 180° - 13x + 3
And then we can write the equation:
C + B + A = 180°
55 + 3x + 2 + 180 -13x - 3 = 180
55 + 3x + 2 - 13x + 3 = 0
60 - 10x = 0
60 = 10x
60/10 = x
6 = x
Then the measures are:
BAC = 180° - 13*6 + 3 = 105°
FAB = 13*6 - 3 = 75°