What, if anything, is wrong with the following: 306 base 4

Unless you're doing something out of the ordinary, the only digits that will appear in a base-4 number are the four digits 0, 1, 2, 3. The digit 6 is unexpected.

If you assign the squiggle that looks like "6" a value of one or two, then this is a legitimate base-four number. You might find it hard to communicate with others that don't share that understanding.

< 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⭐