Nilai B = ... (Gambar soal di : ⬆) A. 23 B. 25 C. 42 D. 65 Tolong sertakan cara pengerjaannya !

➡Sudut Garis lurus = 180°

Maka :

5a +65° = 180°
5a = 180° - 65°
5a = 115°
a = 115/5
a = 23°

Maka :
(a + b) + 5a = 180
6a + b = 180
6(23°) + b = 180
138 + b = 180
b = 180 - 138
b = 42° ➡Opsi C