Tina missed this problem on her test.

what was her mistake?

the multiplication is wrong in part a.
the multiplication is wrong in part b.
the place holder was left out in part b.
the decimal was moved too many places in part c.

The decimal was moved too many places in part C.

Step-by-step explanation:

< 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⭐

chicken chicken chicken

step-by-step explanation: