tolong dijwb secepatnya, pakai cara

besar sudut = 180 derajat
< AOB = 180 - 30 = 150 derajat
2x + 8x = 150 derajat
x = 150 / ( 8 + 2 ) . ( pindah ruas )
x = 150 / 10 = 15
x = 15 derajat
< AOB = 8x
< AOB = 8 . 15
< AOB = 120 derajat