Which pair of vertices is not connected by edgea) s and qb) s and tc) q and rd) u and r

< 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⭐

180-142=38 for the acute angle next to the entry

90+38=128

180-128=52

a=52

step-by-step explanation: