Step-by-step explanation:
3x-28=2x-9
3x-2x=28-9
x=19°
For angle FGH = 2x-9° = 38°-9° = 29°.
For angle HGI = 3x-28° = 57°-28° = 29°.
For angle FGI = 29°+29° = 58°.
hope this helps you.