Besar sudut ACB adalah

Mapel : Matematika
Materi : Garis dan Sudut
Kelas : 7


☣ Sudut Garis Lurus = 180°

Sudut B :
= 180° - 5x

Sudut C
= 180° - (4x - 5)
= 180° - 4x + 5°
= 185° - 4x


☣ Jumlah Sudut ∆ = 180°

▶ Tentukan Nilai x

A + B + C = 180°
40° + (180° - 5x) + (185° - 4x) = 180°
-9x + 405° = 180°
9x = 405° - 180°
9x = 225°
x = 225°/9
x = 25°

Maka, Nilai Sudut ACB
= 185° - 4x
= 185° - 4(25°)
= 185° - 100°
= 85°


Jawaban B ☣