perhatikan gambar ,maka sudutABC pake cara y

2x + 2x + 5 + 4x + 10 = 180°
8x = 180 - 5 - 10
8x = 165
x = 165/8
x = 20,625°

sudut ABC
=> 2x + 5
=> 2(20,625) +5
=> 41,25 + 5
=> 46,25°