tolong bantu aku dong pakai caranya ya!!

2x + (3x - 20) = 180
5x - 20 = 180
5x = 200
x = 40

2x ⇒ 2(40) = 80

70 + 80 + x' = 180
150 + x' =180
x' = 30

x' = sudut BAC
∠ BAC = 30°