What are units of measure and dont use that much mathy terms? hallp.

okay idk if im right but...i think...units of measure means   means like are feet,miles,kilomoters,cenimeters.

i think...hope this helps,theres a good chance im wrong

< 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⭐