B is the midpoint of AC. If AB = x + 5 and BC = 2x – 11, find the measure of AB. А
7
B
16
21
D
42

21

Step-by-step explanation:

AB = BC GIVEN

X+5=2X-11

X=16

HENCE AB=X+5=16

< 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⭐