6 1/2 - 7/8 divided by 5 11/16 ok ok i said i might do one of these on weekdays only but just one more 'cuz i like to see your reactions when you get five stars.(fractions only)

< coa = 150 ( given)

as ba and bc are tangents

so oc and oa is perpendicular to cb and ab respectively because in circle normal passes through centre

so in quadrilateral oabc

< coa + < oab + < ocb + < abc = 360

150 +90+90 + < abc = 360

330 + < abc = 360

< abc = 360 -330 = 30

so < abc = 30

⭐dhruv⭐