Pakek cara ya please

5a+4 + 7a+8 = 180 (berpelurus)
12a+12 = 180
12a = 168
a = 14

besar cbd = 7(14)+8 = 98+8 = 106 (B)

Jawabanya ;

(5a + 4) + (7a + 8) = 180
180 = (5a + 7a) + (4 + 8)
180 = 12a + 12
12a = 180 - 12
12a = 168
a = 168/12
a = 14°

Besar sudut CBD
= 7(a) + 8
= 7(14) + 8
= 98 + 8
= 106°
Pilihan B

- Anna❤