Bingung sama soalnya

Nomor 21]

Mapel : Matematika

Kelas : 7

Bab : Garis dan Sudut
________________

a + b = 65°

⏩Sudut Garis Lurus = 180°

Maka,

a + b + 5a = 180°

65° + 5a = 180°

5a = 180° - 65°

5a = 115

a = 115/5

a = 23°

⏩ a + b = 65°

a + b = 65°

23° + b = 65°

b = 65° - 23°

b = 42° → Opsi C