Sum of all angles inside of a triangle equal 180 degree
The sum of obtuse angles (the one inside of the triangle, bottom right and the one next to is ) must total 180 degrees
so first I would do the obtuse ones
180 = x +15x-4
180 = 16x - 4
184 = 16x
x = 11.5 degrees
so now I would do the inside triangle angles...tell me what you got