Which of the following equations is written in vertex form? A) y = (x + 1)(x − 2) B) y = (x + 1)

2 + 4 C) y = x

2 + 2x − 3

D) 2x
2 + 7 − 5x E) None of these

< 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⭐