yg pinter matematika bantu saya dong no 80

x = 180-83 = 97°
y = 115°
z = 75°

(x + y - z) - ( z - y - x )
= (97 + 115 - 75) - (75-115-97)
= 137 - (-137)
= 137 x 2
= 274°

jawaban : A