Given that lines a and b are parallel and that m∠4 = 128°, find m∠7.

a) 32°
b) 42°
c) 52°
d) 62°

Option 'c' is correct.

Step-by-step explanation:

Since we have given that

line a and line b are two parallel lines.

and there is a transversal.

Since m∠4 = 128°

And m∠4 and m∠8 are corresponding angles.

So, m∠4 = 128° = m∠8

Now, m∠7+m∠8=180° (linear pair)

Hence, Option 'c' is correct.

< 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⭐